WO1998035204A1 - Background compensation for confocal interference microscopy - Google Patents
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- WO1998035204A1 WO1998035204A1 PCT/US1998/001214 US9801214W WO9835204A1 WO 1998035204 A1 WO1998035204 A1 WO 1998035204A1 US 9801214 W US9801214 W US 9801214W WO 9835204 A1 WO9835204 A1 WO 9835204A1
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- G—PHYSICS
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- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/0004—Microscopes specially adapted for specific applications
- G02B21/002—Scanning microscopes
- G02B21/0024—Confocal scanning microscopes (CSOMs) or confocal "macroscopes"; Accessories which are not restricted to use with CSOMs, e.g. sample holders
- G02B21/0052—Optical details of the image generation
- G02B21/0056—Optical details of the image generation based on optical coherence, e.g. phase-contrast arrangements, interference arrangements
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02015—Interferometers characterised by the beam path configuration
- G01B9/02027—Two or more interferometric channels or interferometers
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02041—Interferometers characterised by particular imaging or detection techniques
- G01B9/02042—Confocal imaging
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
- G01B9/02055—Reduction or prevention of errors; Testing; Calibration
- G01B9/02056—Passive reduction of errors
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/0004—Microscopes specially adapted for specific applications
- G02B21/002—Scanning microscopes
- G02B21/0024—Confocal scanning microscopes (CSOMs) or confocal "macroscopes"; Accessories which are not restricted to use with CSOMs, e.g. sample holders
- G02B21/0036—Scanning details, e.g. scanning stages
- G02B21/004—Scanning details, e.g. scanning stages fixed arrays, e.g. switchable aperture arrays
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/0004—Microscopes specially adapted for specific applications
- G02B21/002—Scanning microscopes
- G02B21/0024—Confocal scanning microscopes (CSOMs) or confocal "macroscopes"; Accessories which are not restricted to use with CSOMs, e.g. sample holders
- G02B21/0052—Optical details of the image generation
- G02B21/006—Optical details of the image generation focusing arrangements; selection of the plane to be imaged
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/0004—Microscopes specially adapted for specific applications
- G02B21/002—Scanning microscopes
- G02B21/0024—Confocal scanning microscopes (CSOMs) or confocal "macroscopes"; Accessories which are not restricted to use with CSOMs, e.g. sample holders
- G02B21/0052—Optical details of the image generation
- G02B21/0068—Optical details of the image generation arrangements using polarisation
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/0004—Microscopes specially adapted for specific applications
- G02B21/002—Scanning microscopes
- G02B21/0024—Confocal scanning microscopes (CSOMs) or confocal "macroscopes"; Accessories which are not restricted to use with CSOMs, e.g. sample holders
- G02B21/008—Details of detection or image processing, including general computer control
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
- G11B7/005—Reproducing
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/14—Heads, e.g. forming of the optical beam spot or modulation of the optical beam specially adapted to record on, or to reproduce from, more than one track simultaneously
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B2290/00—Aspects of interferometers not specifically covered by any group under G01B9/02
- G01B2290/45—Multiple detectors for detecting interferometer signals
Definitions
- This invention is related to optical, acoustical, and electron imaging, including utilizing such images to perform precision measurements on biological, integrated circuit, and other samples.
- FM wide field method
- Two-Photon Laser Scanning Fluorescence Microscopy uses a conventional microscope to sequentially acquire a set of images of adjacent focus planes throughout the volume of interest. Each image is recorded using a cooled charge-coupled device (CCD) image sensor (J. Kristian and M.
- CCD charge-coupled device
- Blouke "Charge-coupled Devices in Astronomy," Sci . Am . 247, 67- 74, 1982) and contains data from both in-focus and out-of-focus image planes .
- Kawata, 0. Nakamura, T. Noda, H. Ooki, K Ogino, Y. Kuroiwa, and S. Minami "Laser Computed-Tomography Microscope," Appl. Opt. 29, 3805-3809 (1990) is based on a principal that is closely . related to the technique of X-ray computed tomography, but uses three-dimensional volume reconstruction rather than two- dimensional slice reconstruction. Projected images of a thick three-dimensional sample are collected with a conventional transmission microscope modified with oblique illumination optics, and the three-dimensional structure of the interior of the sample is reconstructed by a computer.
- the data is acquired in a time short compared to that required to process data for a three-dimensional image.
- the 80x80x36-voxel reconstruction required several minutes to collect all projections and send them to a minicomputer. Approximately thirty minutes then were required for digital reconstruction of the image, in spite of utilizing a vector processor at a speed of 20 million floating point operations per second (MFLOPS) .
- MFLOPS floating point operations per second
- a point or pinhole-confocal microscope In a conventional point or pinhole-confocal microscope, light from a point source is focused within a very small space, known as a spot. The microscope focuses light reflected from, scattered by, or transmitted through the spot onto a point detector. In a reflecting point-confocal microscope the incident light is reflected or back-scattered by that portion of the sample in the spot. Any light which is reflected or back- scattered by the sample outside of the spot is not well focused onto the detector, thus it is spread out so the point detector receives only a small portion of such reflected or back- scattered light. In a transmitting point-confocal microscope, incident light is transmitted unless it is scattered or absorbed by that portion of the sample in the spot. Generally, the point source and point detector are approximated by placing masks containing a pinhole in front of a conventional light source and a conventional detector, respectively.
- a line source in a conventional slit-confocal microscope system, light from a line source is focused into a very narrow elongated space, which is also known as a spot.
- the slit- confocal microscope focuses light reflected from, scattered by or transmitted through the spot onto a line detector.
- the line source and line detector can be approximated using a mask with a slit in front of a conventional light source and row of conventional detectors, respectively.
- a line source can be approximated by sweeping a focused laser beam across the object to be imaged or inspected.
- the raw image data are typically stored and later processed to form a two-dimensional cross-section or a three-dimensional image of the object that was inspected or imaged.
- the reduced sensitivity to out-of- focus images relative to conventional microscopy leads to improved statistical accuracy for a given amount of data and the processing operation is considerably simpler in comparison to that required when processing data obtained in conventional microscopy approach.
- the Tandem Scanning Optical Microscope In a system known as the Tandem Scanning Optical Microscope (TSOM) , a spiral pattern of illumination and detector pinholes are etched into a Nipkow disk so, as the disk rotates, the entire stationary object is scanned in two dimensions [ cf. M. Petran and M. Hadravsky, "Tandem-Scanning Reflected-Light Microscope,” J. Opt . Soc . A . 58(5), 661-664 (1968); G. Q. Xiao, T. R. Corle, and G. S. Kino, "Real-Time Confocal Scanning Optical Microscope," Appl . Phys . Lett . 53, 716-718 (1988)].
- the TSOM is basically a single point confocal microscope with a means for efficiently scanning a two-dimensional section one point at a time.
- microlens-array confocal arrangement of Tiziani and Uhde, ibid has out-of-focus image discrimination that is the same as using a multi-pinhole source and multielement detector in a confocal configuration.
- Such a system allows for a number- of points to be examined simultaneously but at a compromise in discrimination against out-of-focus images.
- the Tiziani and Uhde, ibid, system has serious limitations in axial range. This range cannot exceed the focal length of the microlens, which is proportional to the diameter of the microlens for a given numerical aperture. Therefore, as the density of the microlenses is increased, there is an associated decrease in the permitted axial range.
- the Kerstens et al . , ibid, system incorporates a number of pinholes and matching pinpoint detectors in a confocal arrangement to allow for a number of points to be examined simultaneously.
- this gain is at a compromise in discrimination against out-of- focus images and as a result an increase in complexity and cost of required subsequent computer deconvolutions .
- the number of different depth slices required depends upon the range of height that must be measured, and also upon the desired height resolution and performance of the optical system. For typical electronics inspection, images of 10 to 100 different depth slices would be required. Furthermore, data in several color bands may be required to differentiate materials. In confocal imaging systems, a separate two-dimensional scan is required for each desired elevation. If data for multiple color bands is desired, then multiple two-dimensional scans at each elevation are required. By shifting the focus level, similar data can be obtained from adjacent planes and a three- dimensional intensity data set can be acquired.
- none of the prior art confocal microscopy systems can be configured for rapid and/or reliable three-dimensional tomographic imaging, especially in the field of inspection or imaging .
- the confocal approach is more straightforward and works better, for example in confocal fluorescence work, when the concentration of stained structure is high, the conventional microscopy approach still has several practical advantages . The most important of these is that the latter can utilize dyes that are excited in the ultraviolet (UV) range and these often seem more robust and efficient than those excited in the visible range.
- UV ultraviolet
- a UV laser can be incorporated as the light source of a confocal microscope [M. Montag, J. Kululies, R. J ⁇ rgens, H. Gundlach, M. F. Trendelenburg, and H. Spring, "Working with the Confocal Scanning UV-Laser Microscope: Specific DNA Localization at High Sensitivity and Multiple- Parameter Fluorescence," J.
- the cooled CCD detectors used in conventional microscopy systems collect the data in parallel rather than serially, as does the photomultiplier (PMT) in a confocal microscopy system.
- PMT photomultiplier
- the three- dimensional data recording rate of the conventional microscopy system may prove to be significantly higher than that of the confocal microscopy system, even though the time needed for computer deconvolution computations means that there might be an additional delay before the data could be actually viewed as three-dimensional image.
- the signal-to-noise ratio in relation to statistical accuracy must also be considered when making a choice between a CCD detector used to record in parallel a two-dimensional data array and a slit or pinhole confocal microscope.
- the well capacity of a two-dimensional CCD pixel is of the order of 200,000 electrons. This limits the statistical accuracy that can be achieved in a single exposure as compared to that achievable with other photoemissive detectors such as PMT's or photovoltaic devices.
- the residual signals from the out-of-focus images for the system chosen can be comparable to or larger than the in-focus signals.
- a system such as a slit confocal microscope over a standard microscope, or a single pinhole confocal microscope over a slit confocal microscope
- the residual signals from the out-of-focus images for the system chosen can be comparable to or larger than the in-focus signals.
- the single pinhole confocal microscope as well as the slit confocal microscope when looking for an in-focus image signal that is much smaller than the residual out-of-focus image signals.
- Optical coherence-domain reflectometry has been used to obtain information about the three-dimensional properties of a system. This method is described in the following articles: (1) “Optical Coherence- Domain Reflectometry : A New Optical Evaluation Technique,” by R. C. Youngquist, S. Carr, and D. E. N. Davies, Opt. Lett. 12(3), 158-160 (1987); (2) “New Measurement System for Fault Location in Optical Waveguide Devices Based on an Interferometric
- the OCDR method differs from the coherent optical time domain reflectometry (OTDR) technique in that instead of a pulsed light source one uses a broadband continuous-wave source with a short coherence length.
- the source beam enters an interferometer in which one arm has a movable mirror, with the reflected light from this mirror providing a reference beam, and the other arm contains the optical system being tested.
- the interference signal in the coherently mixed reflected light from the two arms is detected by the usual heterodyne method and yields the desired information about the optical system.
- the heterodyne detection of the backscattered signals in the OCDR technique is accomplished by the method of "white-light interferometry, " in which the beam is split into the two arms of an interferometer, reflected by the adjustable mirror and the backscattering site, and coherently recombined.
- Reference (1) also describes a modified method in which the mirror in the reference arm oscillates at a controlled frequency and amplitude, causing a Doppler shift in the reference signal, and the recombined signal is fed into a filtering circuit to detect the beat frequency signal.
- reference (2) Another variation of this technique is illustrated in reference (2), in which the reference arm mirror is at a fixed position and the difference in optical path lengths in the two arms may exceed the coherence length.
- the combined signal is then introduced into a second Michelson interferometer with two mirrors, one fixed in position and the other being moveable.
- This moveable mirror is scanned and the difference in path length between the arms of the second interferometer compensates for the delay between the backscattered and reference signals at discrete positions of the moveable mirror corresponding to the scattering sites.
- an oscillating phase variation at a definite frequency is imposed on the signal from the backscattering site by means of a piezoelectric transducer modulator in the fiber leading to this site.
- the output signal from the second Michelson interferometer is fed to a lock-in amplifier, which detects the beat frequency signal arising from both the piezoelectric transducer modulation and the Doppler shift caused by the motion of the scanning mirror.
- This technique has been used to measure irregularities in glass waveguides with a resolution as short as 15 ⁇ m
- an external Michelson interferometer splits a light beam of high spatial coherence but very short coherence length of 15 ⁇ m into two parts: the reference beam (1) and the measurement beam (2). At the interferometer exit, these two components are combined again to form a coaxial dual beam.
- the two beam components which have a path difference of twice the interferometer arm length difference, illuminate the eye and are reflected at several intraocular interfaces, which separate media of different refractive index. Therefore each beam component (1 and 2) is further split into subcomponents by reflection at these interfaces. The reflected subcomponents are superimposed on a photodetector .
- the optical distance between two boundaries within the eye equals twice the interferometer arm length difference, there are two subcomponents that will travel over the same total path length and will consequently interfere.
- Each value of the interferometer arm length difference where an interference pattern is observed is equal to an intraocular optical distance.
- the absolute position of these interfaces can be determined in vivo with a precision of 5 ⁇ m.
- the PCI suffers from limitations due to motion of the object during the time required for the 3-D scanning.
- OCT optical coherent tomography
- Optical interferometric profilers are widely used for three-dimensional profiling of surfaces when noncontact methods are required. These profilers typically use phase-shifting interferometric (PSI) techniques and are fast, accurate, and repeatable, but suffer from the requirement that the surface be smooth relative to the mean wavelength of the light source. Surface discontinuities greater than a quarter-wavelength (typically 150 n ) cannot be unambiguously resolved with a single-wavelength measurement because of the cyclic nature of the interference. Multiwavelength measurements can extend this range, but the constraints imposed on wavelength accuracy and environmental stability can be severe (U.S. Pat. No. 4,340,306 issued July 20, 1982 to N.
- CCM Coherence Probe Microscope
- the phase ambiguity problem can be completely avoided with the use of DIP.
- a parallel beam of a white-light source perpendicularly impinges upon the real wedge of a Fizeau interferometer in front of an apochromatic microscope objective.
- the Fizeau interferometer is formed by the inner surface of the reference plate and the object surface. Then the light is reflected back onto the slit of a grating spectrometer, which disperses the sofar invisible fringe pattern and projects the spectrum onto a linear array detector. On the detector each point of the surface selected by the slit of the spectrometer furnishes a dispersed spectrum of the air gap in the Fizeau interferometer.
- the fringe patterns can be evaluated by use of Fourier-transform and filtering methods to obtain the phase information from the intensity distribution of a wedge-type interferogram.
- DIP phase ambiguity problem
- DIP is not suitable in applications requiring the examination of three-dimensional objects. This is a consequence of the intrinsic relatively large background produced in DIP from out-of-focus images.
- the background problem is comparable to the background problem faced when trying to produce three-dimensional images using standard interference microscopy.
- the confocal interference microscope of Hamilton and Sheppard, ibid measures the reflected signal at only one point at a time in a three- dimensional object making the system sensitive to sample motion during the required data acquisition scan in three dimensions.
- the copending application by Hill et al . , ibid is well suited to reducing the systematic errors introduced in tomographic imaging by background due to out-of-focus images in the object and/or at the detector. This technology is also operative in parallel data acquisition schemes.
- the Hill et al . , ibid, technology utilizes the difference in transverse spatial properties of in-focus and out-of-focus images to discriminate the one from the other.
- What is needed is a system that combines a sensitivity of image data to out-of-focus images that is reduced below that inherent in prior art confocal and confocal interference microscopy systems, the reduced sensitivity of the image data to out-of-focus images being with respect to both systematic and statistical errors; a reduced requirement of computer deconvolutions associated with reduced sensitivity to out-of- focus images; the potential for high signal-to-noise ratios intrinsic to confocal interference microscopy systems; and the potential to measure the complex amplitude of the scattered and/or the reflected light or acoustic beam.
- I provide a method and apparatus for discriminating the complex amplitude of an in-focus image from the complex amplitude of an out-of-focus image by focusing optical radiation from a broadband spatially incoherent point source onto a source pinhole. Rays emanating from the source pinhole are collimated and directed to a first phase shifter. The phase of a first portion of the collimated rays is shifted by the phase shifter to produce a first quantity of phase-shifted rays, and the phase of a second portion of the collimated rays is shifted by the phase shifter to produce a second quantity of phase-shifted rays. The first and second quantities of phase-shifted rays are focused to a first spot.
- Rays of the first quantity of phase-shifted rays emanating from the first spot are collimated and directed to a beam splitter.
- a first portion of the collimated rays pass through the beam splitter to form a first quantity of a probe beam and a second portion of the collimated rays reflected by the beam splitter to form a first quantity of a reference beam.
- Rays of the second quantity of phase-shifted rays emanating from the first spot are collimated and directed to the beam splitter.
- a first portion of the collimated rays pass through the beam splitter to form a second quantity of the probe beam and a second portion of the collimated rays are reflected by the beam splitter to form a second quantity of the reference beam.
- the rays of the first and second quantities of the probe beam are directed to a second phase-shifter.
- the rays of the first quantity of the probe beam are phase shifted to form a third quantity of the probe beam and rays of the second quantity of the probe beam are phase shifted to form a fourth quantity of the probe beam, the net phase shifts produced by the said first and second phase shifters for the third and fourth quantities of the probe beam being the same.
- the third and fourth quantities of the probe beam are focused by a probe lens onto a spot in the object material to thereby illuminate the object material.
- Rays of the first and second quantities of the reference beam are directed to a third phase-shifter. Rays of the first quantity of the reference beam are phase shifted to form a third quantity of the reference beam and rays of the second quantity of the reference beam are phase shifted to form a fourth quantity of the reference beam, the net phase shifts produced by the first and third phase shifters for the third and fourth quantities of the reference beam being the same.
- the third and fourth quantities of the reference beam are focused by a reference lens onto a spot on a reference mirror.
- Reflected and/or scattered rays of the probe beam emanating from the illuminated object in the direction of the probe lens form a scattered probe beam are collimated by the probe lens, and directed to the second phase shifter.
- the phase of a first portion of the collimated rays is shifted to produce a first scattered probe beam quantity of phase-shifted rays
- the phase of a second portion of the collimated rays is shifted to produce a second scattered probe beam quantity of phase-shifted rays.
- Rays of the first and second scattered probe beam quantities are directed to the beam splitter.
- a portion of the first and second scattered probe beam quantities are reflected by the beam splitter to form third and fourth quantities of the scattered probe beam, respectively.
- the collimated rays of the third and fourth quantities of the scattered probe beam are focused by a detector lens onto plane of a detector pinhole. Reflected rays emanating from the spot on the reference mirror in the direction of the reference lens form a reflected reference beam and are collimated and directed by the reference lens to the third phase shifter. The phase of a first portion of the collimated rays is shifted to produce a first reflected reference beam quantity of phase-shifted rays and the phase of a second portion of the collimated rays is shifted to produce a second reflected reference beam quantity of phase-shifted rays. Rays of the first and second reflected reference beam quantities are directed to the beam splitter.
- a portion of the first and second reflected reference beam quantities are transmitted by the beam splitter to form third and fourth quantities of the reflected reference beam, respectively. Collimated rays of the third and fourth quantities of the reflected reference beam are focused by the detector lens onto the plane of the detector pinhole.
- the intensity of the superimposed third and fourth quantities of the scattered probe beam and the third and fourth quantities of the reflected reference beam transmitted by the detector pinhole is measured by a single pixel detector as a first measured intensity value.
- the phases of the third and fourth quantities of the reflected reference beam are shifted by ⁇ radians by a fourth phase shifter to form a fifth and sixth quantities of the reflected reference beam, respectively.
- the intensity of the superimposed third and fourth quantities of the scattered probe beam and fifth and sixth quantities of the reflected reference beam transmitted by the detector pinhole is measured by the single pixel detector as a second measured intensity value.
- the phases of the third and fourth quantities of the reflected reference beam are shifted by an additional - ⁇ /2 radians by the fourth phase shifter to form a seventh and eighth quantities of the reflected reference beam, respectively.
- the intensity of the superimposed third and fourth quantities of the scattered probe beam and the seventh and eighth quantities of the reflected reference beam transmitted by the detector pinhole is measured by the single pixel detector as a third measured intensity value.
- the phases of the third and fourth quantities of the reflected reference beam are shifted by an additional ⁇ radians by the fourth phase shifter to form a ninth and tenth quantities of the reflected reference beam, respectively.
- the intensity of the superimposed third and fourth quantities of the scattered probe beam and the ninth and tenth quantities of the reflected reference beam transmitted by the detector pinhole is measured by the single pixel detector as a fourth measured intensity value.
- the first, second, third, and fourth measured intensity values are sent to a computer for processing.
- the second measured intensity value is subtracted from the first measured intensity value by the computer to yield a measurement of a first component value of the complex amplitude of the scattered probe beam that is in focus at the plane of the detector pinhole with the effects of light from out-of-focus images canceled out.
- the fourth measured intensity value is subtracted from the third measured intensity value by the computer to yield a measurement of a second component value of the complex amplitude of the scattered probe beam that is in- focus in the plane of the detector pinhole with the effects of light from out-of-focus images canceled out.
- the first and second component values of the amplitude of the scattered probe beam are values of orthogonal components and as such, give within a complex constant an accurate measurement of the complex amplitude of the scattered probe beam that is in- focus in the plane of the detector pinhole with the effects of light from out-of-focus images canceled out.
- accurate one-, two-, and three-dimensional representations of the object material are obtained from one-, two-, and three- dimensional arrays, respectively, of the first, second, third, and fourth intensity values acquired through scanning of the object material in one, two, and three dimensions, respectively.
- the scanning of the object material is achieved by systematically moving the object material in one, two, and three dimensions with a translator which is controlled by the computer.
- the computer algorithms may include computer deconvolutions which are known to those skilled in the art should correction for out-of-focus images be desired beyond the compensation achieved by the apparatus of the present invention.
- I provide a method and apparatus for discriminating the complex amplitude of an in-focus image from the complex amplitude of an out-of-focus image by imaging optical radiation from a broadband, spatially extended, spatially incoherent line source onto a linear array of source pinholes comprising the apparatus and electronic processing means of the previously described embodiment wherein the source pinhole of the first embodiment has been replaced by the linear array of source pinholes whose direction is perpendicular to the system optical axis, the detector pinhole of the first embodiment has been replaced by a one-dimensional linear array of detector pinholes, and the single pixel detector of the first embodiment has been replaced by a one-dimensional linear array of detector pixels, the linear arrays of detector pinholes and detector pixels being orientated with the image of the linear array of source pinholes in the in-focus plane at the
- the measured orthogonal complex-amplitude components of the scattered probe beam give within a complex constant an accurate measurement of the complex amplitude of the scattered probe beam that is in-focus at the plane of the linear array of detector pinholes with the effects of light from out-of-focus images canceled out.
- An accurate one-dimensional representation of a linear array of points on a line section of the object is obtained in a direction selected by orientation of the linear array of source pinholes with no scanning required.
- an accurate one-dimensional representation of the object is obtained from two-dimensional arrays of the first, second, third, and fourth intensity values acquired through scanning of the object in the direction selected by the orientation of the linear array of source pinholes over a length equal to the distance between the images in the object of two contiguous source pinholes.
- accurate two- and three-dimensional representations of the object are obtained from two- and three- dimensional arrays, respectively, of the first, second, third, and fourth intensity values acquired through scanning of the object in the direction selected by the orientation of the linear array of source pinholes over a length equal to the distance between the images in the object of two contiguous source pinholes plus scanning of the object in a second dimension and second and third dimensions, respectively.
- the computer algorithms may include computer deconvolutions which are known to those skilled in the art should correction for out- of-focus images be desired beyond the compensation achieved by the apparatus of the present invention.
- Alternative embodiments to the first and second preferred embodiments of the invention include the ability to improve and optimize the signal-to-noise ratio using additional optical means and substantially the same electronic processing means as are employed in the primary apparatus of the first and second preferred embodiments of the invention.
- the additional optical means comprises modified paths for the reference and probe beams whereby the amplitude of reflected reference beam focused on either the detector pinhole for the first embodiment or the linear array of detector pinholes for the second embodiment can be adjusted relative to the amplitude of the scattered probe beam imaged on either the detector pinhole or the linear array of detector pinholes, respectively.
- I provide a method and apparatus for discriminating the complex amplitude of an in-focus image from the complex amplitude of an out-of-focus image with means to improve and optimize the signal-to-noise ratio comprising the apparatus of the previously described first embodiment and an optical means to adjust the amplitude of a reflected reference beam focused on a detector pinhole relative to the amplitude of the scattered probe beam imaged on the detector pinhole.
- Rays from a broadband spatially incoherent point source are focused onto a source pinhole. Rays emanating from the source pinhole are collimated and directed to a first phase shifter.
- phase of a first portion of the collimated rays is shifted to produce a first quantity of phase-shifted rays
- phase of a second quantity of the collimated rays is shifted to produce a second quantity of phase-shifted rays.
- the first and second quantities of phase-shifted rays impinge on a first beam splitter.
- a first portion of the first quantity of phase-shifted rays pass through the first beam splitter to form a first quantity of the probe beam and a second portion of the first quantity of phase shifted rays is reflected by the first beam splitter to form a first quantity of the reference beam.
- a first portion of the second quantity of phase-shifted rays pass through the first beam splitter to form a second quantity of the probe beam and a second portion of the second quantity of phase- shifted rays is reflected by the first beam splitter to form a second quantity of the reference beam.
- the first and second quantities of the probe beam are focused to a first probe beam spot.
- the first and second quantities of the reference beam are focused to a first reference beam spot.
- Rays of the first quantity of the probe beam emanating from the first probe beam spot are collimated and directed to a second beam splitter. A first portion of the collimated rays pass through the second beam splitter to form a third quantity of the probe beam. Rays of the second quantity of probe beam emanating from the first probe beam spot are collimated and directed to the second beam splitter. A first portion of the collimated rays pass through the second beam splitter to form a fourth quantity of the probe beam. The rays of the third and fourth quantities of the probe beam are directed to a second phase shifter. The rays of the third quantity of the probe beam pass through the second phase shifter and are phase shifted to form a fifth quantity of the probe beam. The rays of the fourth quantity of the probe beam pass through the second phase shifter and are phase shifted to form a sixth quantity of the probe beam, the net phase shifts produced by the first and second phase shifters for the fifth and sixth quantities of the probe beam being the same.
- Rays of the first quantity of the reference beam emanating from the first reference beam spot are collimated, directed to a third phase shifter, and emerge as a third quantity of the reference beam.
- Rays of the second quantity of the reference beam emanating from the first reference beam spot are collimated, directed to the third phase shifter, and emerge as a fourth quantity of the reference beam, the net phase shifts produced by the first and third phase shifters for the third and fourth quantities of the reference beam being the same.
- a first portion of the third quantity of the reference beam is reflected by a third beam splitter to form a fifth quantity of the reference beam.
- a first portion of the fourth quantity of the reference beam is reflected by the third beam splitter to form a sixth quantity of the reference beam.
- the collimated fifth and sixth quantities of the probe beam are focused by a probe lens onto a second probe beam spot in the object material to thereby illuminate the object material.
- the collimated fifth and sixth quantities of the reference beam are focused by a reference lens onto a second reference beam spot on the reference mirror.
- the scattered probe beam is collimated by the probe lens and directed to the second phase shifter.
- the phase of a first portion of the collimated rays is shifted to produce a first scattered probe beam quantity of phase-shifted rays
- the phase of a second portion of the collimated rays is shifted to produce a second scattered probe beam quantity of phase-shifted rays .
- Rays of the first and second scattered probe beam quantities are directed to the second beam splitter.
- a portion of the first and second scattered probe beam quantities are reflected by the second beam splitter to form a third and fourth quantities of the scattered probe beam, respectively.
- Collimated rays of the third and fourth quantities of the scattered probe beam are focused by a detector lens to form a scattered probe beam spot in the plane of the detector pinhole.
- Reflected rays emanating from the second reference beam spot in the direction of the reference lens form a reflected reference beam and are collimated and directed to the third beam splitter.
- a portion of the reflected reference beam is transmitted by the third beam splitter and is incident on a fourth phase shifter.
- the phase of a first portion of the incident beam transmitted by the fourth phase shifter is shifted to produce a first reflected reference beam quantity of phase- shifted rays.
- the phase of a second portion of the incident beam transmitted by the fourth phase shifter is shifted to produce a second reflected reference beam quantity of phase- shifted rays. Rays of the first and second reflected reference beam quantities are directed to the second beam splitter.
- a portion of the first and second reflected reference beam quantities are transmitted by the second beam splitter to form a third and fourth quantities of the reflected reference beam, respectively. Collimated rays of the third and fourth quantities of the reflected reference beam are focused by the detector lens to form a reflected reference beam spot in the plane of the detector pinhole.
- the intensity of the superimposed third and fourth quantities of the scattered probe beam and the third and fourth quantities of the reflected reference beam transmitted by the detector pinhole is measured by a single pixel detector as a first measured intensity value.
- the phases of the third and fourth quantities of the reflected reference beam are shifted by ⁇ radians by a fifth phase shifter to form a fifth and sixth quantities of the reflected reference beam, respectively.
- the intensity of the superimposed third and fourth quantities of the scattered probe beam and the fifth and sixth quantities of the reflected reference beam transmitted by the detector pinhole is measured by the single pixel detector as a second measured intensity value.
- the phases of the third and fourth quantities of the reflected reference beam are shifted by an additional - ⁇ /2 radians by the fifth phase shifter to form a seventh and eighth quantities of the reflected reference beam.
- the intensity of the superimposed third and fourth quantities of the scattered probe beam and the seventh and eighth quantities of the reflected reference beam transmitted by the detector pinhole is measured by the single pixel detector as a third measured intensity value.
- the phases of the third and fourth quantities of the reflected reference beam are shifted by an additional ⁇ radians by the fifth phase shifter to form a ninth and tenth quantities of the reflected reference beam.
- the intensity of the superimposed third and fourth quantities of the scattered probe beam and the ninth and tenth quantities of the reflected reference beam transmitted by the detector pinhole is measured by the single pixel detector as a fourth measured intensity value .
- the first, second, third, and fourth measured intensity values are sent to a computer for processing.
- the second measured intensity value is subtracted from the first measured intensity value by the computer to yield a measurement of a first component value of the complex amplitude of the scattered probe beam that is in focus at the plane of the detector pinhole with the effects of light from out-of-focus images canceled out.
- the fourth measured intensity value is subtracted from the third measured intensity value by the computer to yield a measurement of a second component value of the complex amplitude of the scattered probe beam that is in focus in the plane of the detector pinhole with the effects of light from out-of-focus images canceled out.
- the first and second component values of the amplitude of the scattered probe beam are values of orthogonal components and as such, give within a complex constant an accurate measurement of the complex amplitude of the scattered probe beam that is in- focus at the plane of the detector pinhole with the effects of light from out-of-focus images canceled out.
- accurate one-, two-, and three-dimensional representations of the object material are obtained from one-, two-, and three- dimensional arrays, respectively, of the first, second, third, and fourth intensity values acquired through scanning of the object material in one, two, and three dimensions, respectively. Scanning of the object material is achieved by systematically moving the object material in one, two, and three dimensions with a translator which is controlled by the computer.
- the computer algorithms may include computer deconvolutions which are known to those skilled in the art should correction for out- of-focus images be desired beyond the compensation achieved by the apparatus of the present invention.
- the signal-to-noise ratio can be optimized in the third embodiment with respect to .measuring the desired complex amplitudes. The optimization is accomplished by adjusting the ratio of the amplitude of the third and fourth quantities of the scattered probe beam and the amplitude of the third and fourth quantities of the reflected reference beam by altering the reflection-transmission properties of the first, second, and third beam splitters.
- I provide a method and apparatus for discriminating the complex amplitude of an in-focus image from the complex amplitude of an out-of-focus image with means to adjust or optimize the signal-to-noise ratio by imaging optical radiation from a broadband, spatially extended, spatially incoherent source onto a linear array of source pinholes
- the apparatus and electronic processing means of the previously described third embodiment wherein the source pinhole of the third embodiment has been replaced by the linear array of source pinholes whose direction is perpendicular to the optical axis, the detector pinhole of the third embodiment has been replaced by a one-dimensional linear array of detector pinholes, and the single pixel detector of the third embodiment has been replaced by a one-dimensional linear array of detector pixels, the linear arrays of detector pinholes and pixels being aligned with the image of the linear array of source pinholes in the in-focus plane at the linear array of detector pinholes.
- the measured values of the orthogonal complex-amplitude components of the scattered probe beam give within a complex constant an accurate measurement of the complex amplitude of the scattered probe beam that is in- focus in the plane of the linear array of detector pinholes with the effects of light from out-of-focus images canceled out.
- An accurate one-dimensional representation of a linear array of points on a line section of the object is obtained in the direction selected by orientation of the linear array of source pinholes with no scanning required.
- an accurate one-dimensional representation of the object is obtained from two-dimensional arrays of the first, second, third, and fourth intensity values acquired through scanning of the object in the direction selected by the orientation of the linear array of source pinholes over a length equal to the distance between the image in the object of two contiguous source pinholes.
- accurate two- and three-dimensional representations of the object are obtained from two- and three-dimensional arrays, respectively, of the first, second, third, and fourth intensity values acquired through scanning of the object in the direction selected by the orientation of the linear array of source pinholes over a length equal to the distance between the image in the object of two contiguous source pinholes plus scanning of the object in a second dimension and second and third dimensions, respectively.
- Scanning of the object material is achieved by systematically moving the object material in one and two dimensions with a translator which is controlled by the computer.
- the computer algorithms may include computer deconvolutions which are known to those skilled in the art should correction for out-of-focus images be desired beyond the compensation achieved by the apparatus of the present invention.
- the signal-to-noise ratio obtained in the fourth embodiment can be optimized with respect to measuring the desired complex amplitudes.
- the optimization is accomplished by adjusting the ratio of the amplitude of the third and fourth quantities of the scattered probe beam and the amplitude of the third and fourth quantities of the reflected reference beam by altering the reflection-transmission properties of the first, second, and third beam splitters.
- Fifth and sixth alternative preferred embodiments to the first, second, third, and fourth preferred embodiments includes the ability to discriminate the complex amplitude of an in-focus image from the complex amplitude of an out-of-focus image for images obtained from light transmitted through the object material nominally in the same direction as the direction of propagation of the probe beam comprising substantially the same apparatus and electronic processing means of the primary four preferred embodiments with additional optical means.
- the additional optical means preferable comprises interferometer configurations that operate in the prescribed transmission mode.
- the "enabling technology" of the invention applies for any electromagnetic radiation, electron beams as used for example in electron microscopes, or even acoustic waves for which suitable collimating lenses, imaging lenses, and phase shifters can be provided.
- the function of producing the square of the amplitude must be done in the electronic processing following the detector.
- the line source need not be spatially incoherent in the direction of the line source in the case of either the second, fourth, or sixth preferred embodiments to achieve a reduced systematic error although the systematic error will generally be lower when a spatially incoherent line source is used.
- Source can be either a narrow spectral line or a broadened spectral line.
- An advantage of the invention is that the complex scattering amplitude of the object is obtained instead of the magnitude of the scattering amplitude as in the case of PCI and OCT. This is particularly important with respect to the amount of computer analysis required to obtain a given type of one-, two- or three-dimensional image of the object material.
- Another advantage is that the computer processing required to obtain the complex scattering amplitude in one-, two-, and three-dimensional imaging is greatly reduced compared to that required in prior art confocal systems currently employed. Another advantage is that if it is necessary to correct for out-of-focus images which are already greatly reduced in the apparatus of the present invention, the computer processing required with the apparatus of the present invention is significantly reduced compared to the computer processing required in prior art scanning single-pinhole confocal interference microscopy to .achieve a given level of correction.
- Another advantage is that the contribution of background radiation to the statistical noise in the measured complex scattering amplitude at a given point in the object for a given measurement interval of time can be reduced to that which derives principally from the size of the complex scattering amplitude itself, in particular for the case where the amplitude of the background radiation is relatively large compared to the size of desired complex scattering amplitude. This is not achievable in prior art scanning single-pinhole confocal microscopy systems.
- the statistical error in images obtained with the apparatus of the present invention is reduced compared to the statistical error in images obtained with prior art confocal interference microscopy systems.
- the apparatus of the present invention can, in summary, be operated to (1) reduce systematic error, (2) reduce statistical error, (3) reduce dynamic range requirement for detector and processing electronics, (4) reduce the computer processing required to generate either a one-, two-, or three-dimensional image, (5) can be operative with either narrow or broadband sources, and/or (6) can be operative when imaging through a turbid medium. Generally, one or more of these features can be implemented for operation in parallel.
- FIGS, la-j taken together illustrate, in schematic form, the presently preferred first embodiment of the present invention with FIG. la showing optical paths between subsystems 80 and 81, 81 and 82, 81 and 83, 82 and 84, and 83 and 84, paths of the electronic signals from computer 118 to translator 116 and to phase shifter 44 in subsystem 83, and path of electronic signal from detector 114 in subsystem 84 to computer 118;
- FIG. lb illustrates subsystem 80
- FIG. lc illustrates subsystem 81
- FIG. Id illustrates subsystem 82 for the case of probe beam entering subsystem 82
- FIG. l ⁇ illustrates subsystem 83 for the case of reference beam entering subsystem 83
- FIG. If illustrates subsystem 82 for the case of probe beam exiting subsystem 82;
- FIG. lg illustrates subsystem 83 for the case of reference beam exiting subsystem 83
- FIG. lh illustrates subsystem 84 for the case of probe beam entering subsystem 84
- FIG. Ii illustrates subsystem 84 for the case of reference beam entering subsystem 84
- FIG. lj illustrates subsystems 82 and 84 for the case of an out-of-focus beam in subsystem 84 originating from scattering and/or reflection of light in subsystem 82;
- FIGS. 2a-d taken together illustrate, in schematic form, the presently preferred second embodiment of the present invention with FIG. 2a showing optical paths between subsystems 80a and 81, 81 and 82, 81 and 83, 82 and 84a, and 83 and 84a, paths of the electronic signals from computer 118 to translator 116 and to phase shifter 44 in subsystem 83, and path of electronic signal from detector 114a in subsystem 84a to computer 118 ;
- FIG. 2b illustrates subsystem 80a
- FIG. 2c illustrates subsystem 84a for the case of probe beam entering subsystem 84a
- FIG. 2d illustrates subsystem 84a for the case of reference beam entering subsystem 84a
- FIGS. 3a-j taken together illustrate, in schematic form, the presently preferred third embodiment of the present invention with FIG. 3a showing optical paths between subsystems 80 and 81a, 80 and 81b, 81a and 82, 81b and 83a, 82 and 84, and 83a and 84, paths of the electronic signals from computer 118 to translator 116 and to phase shifter 44 in subsystem 83a, and path of electronic signal from detector 114 in subsystem 84 to computer 118;
- FIG. 3b illustrates subsystem 80
- FIG. 3c illustrates subsystem 81a
- FIG. 3d illustrates subsystem 82 for the case of probe beam entering subsystem 82
- FIG. 3e illustrates subsystem 81b
- FIG. 3f illustrates subsystem 83a for the case of reference probe beam entering subsystem 83a
- FIG. 3g illustrates subsystem 82 for the case of probe beam exiting subsystem 82
- FIG. 3 illustrates subsystem 83a for the case of reference beam exiting subsystem 83a
- FIG. 3i illustrates subsystem 84 for the case of probe beam entering subsystem 84
- FIG. 3j illustrates subsystem 84 for the case of reference beam entering subsystem 84
- FIGS. 4a-d taken together illustrate, in schematic form, the presently preferred fourth embodiment of the present invention with FIG. 4a showing optical paths between subsystems 80a and 81a, 80a and 81b, 81a and 82, 81b and 83a, 82 and 84a, and 83a and 84a, paths of the electronic signals from computer 118 to translator 116 and to phase shifter 44 in subsystem 83a, and path of electronic signal from detector 114a in subsystem 84 to computer 118 ;
- FIG. 4b illustrates subsystem 80a;
- FIG. 4c illustrates subsystem 84a for the case of probe beam entering subsystem 84a
- FIG. 4d illustrates subsystem 84a for the case of reference beam entering subsystem 84a
- FIGS. 5a-f taken together illustrate, in schematic form, the presently preferred third embodiment of the present invention with FIG. 5a showing optical paths between subsystems 80b and 82a, 80b and 81b, 82a and 85, 81b and 85, paths of the electronic signals from computer 118 to translator 116 and to phase shifter 44 in subsystem 85, and path of electronic signal from detector 114 in subsystem 85 to computer 118;
- FIG. 5b illustrates subsystem 80b
- FIG. 5 ⁇ illustrates subsystem 82a
- FIG. 5d illustrates subsystem 81b
- FIG. 5 ⁇ illustrates subsystem 85 for the case of probe beam entering subsystem 85
- FIG. 5f illustrates subsystem 85 for the case of reference probe beam entering subsystem 85
- FIGS. 6a-d taken together illustrate, in schematic form, the presently preferred third embodiment of the present invention with FIG. 6a showing optical paths between subsystems 80c and 82a, 80c and 81b, 82a and 85a, 81b and 85a, paths of the electronic signals from computer 118 to translator 116 and to phase shifter 44 in subsystem 85, and path of electronic signal from detector 114a in subsystem 85 to computer 118;
- FIG. 6b illustrates subsystem 80c
- FIG. 6c illustrates subsystem 85a for the case of probe beam entering subsystem 85a
- FIG. 6d illustrates subsystem 85a for the case of reference beam entering subsystem 85a
- FIG. 7 depicts the geometry of a reflecting confocal microscope with three imaging sections
- FIG. 9 is a graph depicting the square of the magnitude of the background amplitude for each of the beams B52D-1, -2 , -3, -4 ( cf. FIG.
- the present invention permits the separation of the complex amplitude of reflected and/or scattered light by a volume element of three-dimensional image space or region from the complex amplitude of the background light produced by superimposed out-of-focus images of structures before, behind, and to the side of the volume element under examination.
- the described tomographic technique can separate a desired complex amplitude signal in an image plane from "background” and "foreground” complex amplitude signals generated by various mechanisms .
- Such background and foreground complex amplitude signals may be (1) out-of-focus images of sections of an object material other than the slice being imaged, (2) scattering of a desired amplitude signal, (3) scattering of signals originating from sources other than the slice being imaged, and/or (4) thermal radiation. Scattering sites and thermal radiation sources may be located in the space before, behind and/or in the object slice under examination.
- the technique of the present invention is implemented with one of two different levels of discrimination against out-of- focus images.
- Level 1 the impulse response functions of imaging subsystems are manipulated in one plane by introducing one dimensional patterns of phase changes at the pupils of respective subsystems of the apparatus of the present invention.
- Level 2 the impulse response functions of imaging subsections are manipulated in two orthogonal planes by introducing two-dimensional patterns of phase changes at the pupils of the respective subsystems.
- a Level 2 implementation leads to a more effective discrimination of out-of-focus images from in-focus images than a Level 1 implementation.
- the linear array of source pinholes may be configured as a slit whereas when using a Level 2 discrimination in the second, fourth, and sixth embodiments, the spacing between source pinholes should be larger than a minimum value in accordance with subsequently set fourth Eq. (38) .
- Level 1 and Level 2 discriminations may be implemented for any of the preferred embodiments that are described.
- the enabling technology of the present invention which is common to each of the preferred embodiments of the apparatus of the present invention configured with either of the Level 1 or Level 2 discriminations is described herein only for the preferred embodiments with Level 1 discrimination. The various physical embodiments and their operation will be described first, and then the supporting theory will be set fourth.
- FIGS, la-j depict in schematic form presently preferred first preferred embodiment of the present invention.
- the preferred embodiment of the present invention is an interferometer comprised of a beam splitter 100, object material 112 supported by xyz translator 116, a reference mirror 120, and a detector 114.
- This configuration is known in the art as a Michelson interferometer, and is shown as a simple illustration.
- Other forms of interferometer known in the art such as a polarized Michelson interferometer and as described in an article entitled "Differential Interferometer Arrangements for Distance and Angle Measurements: Principles, Advantages, and Applications," by C. Zanoni (VDI Berichte NR. 749, 93-106, 1989) may be incorporated into the apparatus of FIGS, la-j without significantly departing from the spirit and scope of the preferred first embodiment of the present invention.
- FIG. lb depicts in schematic form one embodiment of the subsystem 80 shown in FIG. la.
- light source 10 is preferably a point source or a spatially incoherent source of radiation across the surface of the source, preferably a laser or like source of coherent or partially coherent radiation, and preferably polarized.
- Light source 10 emits input beam 2 aligned with optical axis 3 of subsystem 80.
- input beam 2 enters focusing lens 6 and is focused at pinhole 8 in image plane 7.
- Light beam 12 comprised of a plurality of light beams 12-1,-2,-3,-4 diverges from the pinhole 8 and enters lens 16 having an optical axis aligned with optical axis 3 of subsystem 80.
- Phase shifter 14 is comprised of rectangular phase shifters 14-1,-2,- 3,-4 which are located so that their respective optical axes are parallel to optical axis 3 of subsystem 80.
- the number of phase shifters may be any suitable number 2ra , m being an integer.
- Parallel light beams 12A- 1,-2,-3,-4 pass through phase shifters 14-1,-2,-3,-4, respectively, and emerge from phase shifter 14 as light beams 12B-1, -2, -3 , -4 , respectively, which comprise light beam 12B.
- Each of the phase shifters 14-2 and 14-4 introduce a phase shift of I radians more than the phase shift introduced by each of the phase shifters 14-1 and 14-3, the phase shifts introduced by phase shifters 14-1 and 14-3 being the same.
- light beam 12B exits subsystem 80 and enters subsystem 81.
- light beam 12B enters lens 26 and emerges as light beam 12C comprised of light beams 12C-1, -2 , -3 , - 4.
- Lens 26 focuses light beam 12C to point image 18 in in-focus image plane 17.
- Light beam 12C emerges from point image 18 as light beam 22 comprised of light beams 22-1,-2,-3,-4.
- Light beam 22 enters lens 36 having an optical axis aligned with optical axis 3 subsystem 81.
- Light beam 22 emerges from lens 36 and exits subsystem 81 as collimated light beam 22A comprised of light beams 22A-1, -2, -3 , -4.
- light beam 22A is partially transmitted by beam splitter 100 as light beam P22B comprised of light beams P22B-1, -2, -3 , -4 and enters subsystem 82 which is shown in FIG. Id.
- phase shifter 24 comprised of phase shifters 24-1,-2,-3,-4.
- Light beams P22B-l,-2,- 3,-4 pass through phase shifters 24-1,-2,-3,-4, respectively, and emerge as light beam P22C comprised of light beams P22C-1,- 2,-3,-4, respectively.
- the phase shifts introduced by phase shifters 24-1 and 24-3 are of equal values which are ⁇ radians more than the phase shift introduced by either phase shifter 24- 2 or 24-4, the phase shifts introduced by phase shifters 24-2 and 24-4 being of equal values.
- phase shifters 14-1 and 24-1, 41-2 and 24-2, 14-3 and 24-3, and 14-4 and 24-4 is ⁇ radians.
- Light beam P22C passes through lens 46 as light beam P22D comprised of light beams P22D-1, -2, -3 , -4 which is focused to point image 28 in in-focus image plane 27 in object material 112.
- Optical axis of lens 46 is aligned with optical axis 3 of subsystem 82.
- light beam 22A is partially reflected by beam splitter 100 as light beam R22B comprised of light beams R22B- 1,-2,-3,-4.
- Light beam R22B enters subsystem 83 which is shown in FIG. l ⁇ .
- phase shifter 34 comprised of phase shifters 34-1,-2,-3,-4.
- Light beam R22B passes through phase shifter 34 and then through phase shifter 44 to emerge as light beam R22C comprised of light beams R22C-1, -2 , -3 , -4.
- phase shift introduced by phase shifter 44 is controlled by signal 132 from computer 118.
- the phase shifts introduced by phase shifters 34-1 and 34-3 are of equal values which are ⁇ radians more than the phase shift introduced by either phase shifter 34-2 or 34-4, the phase shifts introduced by phase shifters 34-2 and 34-4 being of equal values.
- Light beam R22C passes through lens 56 as light beam R22D comprised of light beams R22D-l,-2,- 3,-4.
- Light beam R22D is focused by lens 56 to point image 38 in in-focus image plane 37 on reference mirror 120.
- Optical axis of lens 56 is aligned with optical axis 3a of subsystem 83.
- a portion of light beam P22D ⁇ cf . FIG. Id) is reflected and/or scattered by the object material at point image 28 as a plurality of light beams P32-1, -2, -3 , -4 comprising light beam P32.
- Light beam P32 diverges from point image 28 in in- focus image plane 27 and enter lens 46.
- light beam P32 emerges from lens 46 as collimated light beam P32A comprised of light beams P32A-1, -2, -3 , -4.
- Light beams P32A-1, -2, -3, -4 pass through phase shifters 24-4,-3,-2,-1, respectively, and emerge as light beams P32B-1, -2, -3 , -4, respectively.
- Light beams P32B-1, -2, -3, -4 comprise light beam P32B which exits subsystem 82.
- the phase shifts introduced by phase shifters 24-1 and 24-3 are of equal values which are ⁇ radians more than the phase shift introduced by either phase shifter 24-2 or 24-4, the phase shifts introduced by phase shifters 24-2 and 24-4 being of equal values.
- light beam R22D ( cf. FIG. le) is reflected by reference mirror 120 as light beam R32 comprised of light beams R32-1, -2, -3 , -4.
- Light beam R32 diverges from point image 38 in in-focus image plane 37 and enters lens 56.
- light beam R32 emerges from lens 56 as collimated light beam R32A comprised of light beams R32A-1, -2, -3 , -4.
- phase shifter 44 passes first through phase shifter 44 and then through phase shifters 34-4, -3, -2-, -1, respectively, to emerge as light beams R32B-1, -2 , -3 , -4, respectively.
- the phase shift introduced by phase shifter 44 is controlled by signal 132 from computer 118.
- the phase shifts introduced by phase shifters 34-1 and 34- 3 are of equal values which are ⁇ radians more than the phase shift introduced by either phase shifter 34-2 or 34-4, the phase shifts introduced by phase shifters 34-2 and 34-4 being of equal values.
- Light beams R32B-1, -2, -3 , -4 comprise light beam R32B which exits subsystem 83.
- light beam P32B is partially reflected by beam splitter 100 as light beam P32C which is comprised of light beams P32C-1, -2, -3 , -4.
- Light beam P32C enters subsystem 84 which is shown in FIG. lh, passes through lens 66 and emerges as light beam P32D comprised of light beams P32D-1, -2, -3, -4.
- Light beam P32D is focused by lens 66 to point image 48 in in-focus image plane 47 on single pixel detector 114.
- Optical axis of lens 66 is aligned with subsystem optical axis 3b of cell 84. It is shown in FIG.
- light beam R32B is partially transmitted by beam splitter 100 as light beam R32C comprised of light beams R32C-1, -2 , -3, -4.
- Light beam R32C enters subsystem 84 shown in FIG. Ii .
- FIG. Ii light beam R32C passes through lens 66 and emerges as light beam R32D comprised of light beams R32D-1, -2, -3, -4.
- Light beam R32D is focused by lens 66 to point image 48 in in-focus image plane 47 on single pixel detector 114.
- FIG. 1j a portion of light beam P22 ⁇ cf .
- FIGS, la and Id is reflected and/or scattered by the object material at an "out-of-focus" point image -58 in out-of-focus image plane 57 as light beam B52 comprised of a plurality of light beams B52-1,- 2,-3,-4.
- Light beam B52 diverges from out-of-focus point image 58 and enter lens 46.
- FIG. 1j light beam B52 emerges from lens 46 as substantially collimated light beam B52A comprised of light beams B52A-1, -2, -3, -4.
- Light beams B52A-1,- 2,-3,-4 pass through phase shifters 24-4,-3,-2,-1, respectively, and emerge as light beams B52B-1, -2, -3, -4, respectively.
- Light beams B52B-1, -2, -3 , -4 comprise light beam B52B.
- the phase shifts introduced by phase shifters 24-1 and 24-3 are of equal values which are ⁇ radians more than the phase shift introduced by either phase shifter 24-2 or 24-4.
- Light beam B52B is partially reflected by beam splitter 100 as light beam B52C comprised of light beams B52C-1, -2 , -3, -4.
- Light beam B52C passes through lens 66 and emerges as light beam B52D comprised of light beams B52D-1, -2, -3, -4.
- Light beam B52D is focused by lens 66 onto point image 68 in out-of-focus image plane 67 which is displaced from the in-focus image plane 47.
- the operation of the apparatus of the present invention depicted in FIGS, la-j is based on the acquisition of a sequence of four intensity measurements by the single pixel detector 114.
- the sequence of the four intensity values /, , I 2 , 7 3 , and 7 4 are made by the single pixel detector 114 with phase shifter 44 introducing a sequence of phase shifts (the total phase shift of the reference beam which includes the phase shifts produced in passing through phase shifter 44 in both directions) ⁇ 0 , ⁇ 0 + ⁇ , ⁇ 0 + ⁇ /2, and ⁇ 0 +3 ⁇ /2 radians, respectively, where ⁇ 0 is some fixed value of phase shift.
- phase shifters 34 and 44 could be combined into a single phase shifter controlled by the computer 118.
- the four intensity values 7, , I 2 , I 3 , and 7 4 are sent to computer 118 as signal 131, in either digital or analog format, for subsequent processing.
- Conventional conversion circuitry, i . e . , analog-to-digital converters, is included in either detector 114 or computer 118 for converting the four intensity values 7, , I 2 , 7 3 , and 7 4 to a digital format.
- the phase shift of phase shifter 44 is controlled by signal 132 which is generated and subsequently transmitted by computer 118 in accordance with subsequently set fourth Eq. (25) .
- Phase shifter 44 can be of the electro-optical type or the type subsequently described herein for use in broadband operation with respect to optical wavelength.
- the intensity differences / x - 7 2 and 7 3 -7 4 are then computed by computer 118 according to subsequently set fourth Eqs . (24a) and (24b) and these differences contain with relatively high efficiency only the interference cross term between the complex amplitude of the in-focus scattered probe beam P32D and the complex amplitude of the in-focus reflected reference beam R32D.
- FIG. lh) and the complex amplitude of the in-focus reflected reference beam R32D ( cf . FIG. Ii) is a consequence of two system properties.
- the first system property is that within a complex scale factor, the spatial distributions of the complex amplitudes of the in-focus scattered probe beam P32D and the in-focus reflected reference beam R32D at in-focus point image 48 are substantially the same for an arbitrary phase shift introduced by the phase shifter 44.
- the second system property is that the interference cross term between the complex amplitude of the in-focus scattered probe beam P32D and the complex amplitude of the in-focus reflected reference beam R32D changes sign when the phase shift introduced by phase shifter 44 is incremented or decremented by ⁇ ,3 ⁇ , ... radians . Since the interference cross term between the complex amplitude of the in-focus scattered probe beam P32D and the complex amplitude of the in-focus reflected reference beam R32D changes sign when the phase shift introduced by phase shifter 44 is incremented or decremented by ⁇ , 3 ⁇ , ... radians, this interference cross term does not cancel out in the intensity differences 7, - 7 2 and 7 3 -7 4 . However, all non interference cross terms, i.e.
- the intensities of the in-focus scattered probe beam P32D and of the in-focus reflected reference beam R32D will cancel out in the intensity differences 7, - 7 2 and 7 3 -7 4 .
- the referenced system properties are features that are in common with the confocal interference microscope and henceforth will be referred to as the "confocal interferometric system property" .
- the intensity differences 7,-7 2 and 7,-7 4 will contain only the interference cross term between the complex amplitude of the out-of-focus scattered probe beam B52D and the complex amplitude of the in-focus reflected reference beam R32D as a consequence of the confocal interferometric system property.
- the size of the interference cross term between the complex amplitude of the out-of-focus scattered probe beam B52D and the complex amplitude of the in-focus reflected reference beam R32D will be greatly reduced in relation to the corresponding interference cross term in the prior art confocal interference microscope.
- the interference cross term between the complex amplitude of the out-of-focus scattered probe beam B52D and the complex amplitude of the in-focus reflected reference beam R32D is representative of the background from out-of-focus images.
- the size of the interference cross term between the complex amplitude of the out-of-focus scattered probe beam B52D and the complex amplitude of the in-focus reflected reference beam R32D is in general reduced in magnitude whereas there is substantially no reduction in the magnitude of the interference cross term between the complex amplitude of the in-focus scattered probe beam P32D and the complex amplitude of the in-focus reflected reference beam R32D.
- the reduction of the interference cross term between the complex amplitude of the out-of-focus scattered probe beam B52D and the complex amplitude of the in-focus reflected reference beam R32D follows in part from the fact that the amplitude of a beam decreases as the distance to the image plane is increased. This property is the basis of the reduced background in prior- art confocal interference microscopy.
- the reduction in the magnitude of the interference cross term between the complex amplitude of the out-of-focus scattered probe beam B52D and the complex amplitude of the in-focus reflected reference beam R32D is enhanced in relation to that achieved in prior-art confocal interference microscopy.
- phase shifters 14, 24, and 34 modify the spatial properties of the complex amplitudes of the in-focus scattered probe beam P32D, the in-focus reflected reference beam R32D, and the out-of-focus scattered probe beam B52D at the in-focus image plane 47.
- the spatial properties of the complex amplitudes of the in-focus scattered probe beam P32D and the in- focus reflected reference beam R32D are both modified by the phase shifters 14, 24, and 34, the modified spatial distributions of their respective complex amplitudes are substantially the same.
- the respective modified spatial distributions of the complex amplitude of the out-of-focus scattered probe beam B52D and the complex amplitude of the in-focus reflected reference beam R32D on the in-focus image plane 47 are distinctly different.
- the complex amplitude of the in-focus reflected reference beam R32D is an antisymmetric function about the center of the in-focus reflected reference beam R32D.
- that part of the out-of-focus scattered probe beam B52D which interferes with the complex amplitude of the in-focus reflected reference beam R32D is the complex amplitude associated principally with one of the light beams B52D-1, -2 , -3, or B52D-4 as shown in FIG.
- the spatial distribution of the interference cross term between the complex amplitude of the out-of-focus scattered probe beam B52D and the complex amplitude of the in-focus reflected reference beam R32D is comprised primarily of an antisymmetric distribution about the center of the in-focus reflected reference beam R32D.
- the contribution of the interference cross term between the complex amplitude of the out-of-focus scattered probe beam B52D and the complex amplitude of the in-focus reflected reference beam R32D to the intensity value recorded by the single pixel detector 114 at point image 48 is the integral of this interference cross term across the space of the in-focus image of the reflected reference beam R32D.
- phase shifter 14 Insight into the interrelationship between phase shifters 14, 24, and 34 may also be gained by considering what would be the consequence should phase shifter 14 be removed from the first embodiment.
- the in-focus reflected reference beam R32D would change from an antisymmetric function to a symmetric function with no substantial change in the spatial properties of the out-of-focus scattered probe beam B52D.
- the spatial distribution of the interference cross term between the complex amplitude of the out-of-focus scattered probe beam B52D and the complex amplitude of the in-focus reflected reference beam R32D would be comprised primarily of an symmetric distribution about the center of the in-focus reflected reference beam R32D.
- FIG. 2a depicts in schematic form a second embodiment of the instant invention in which the source subsystem 80a and the detector subsystem 84a are preferably configured for slit confocal microscopy.
- the source subsystem 80a and the detector subsystem 84a are preferably configured for slit confocal microscopy.
- Like reference numerals are used in FIGS. 2a-d for like elements previously described with reference to FIGS. la-j.
- FIGS. 3a-j there is shown an alternative third embodiment of the present invention in which the paths for the reference and probe beams of the first preferred embodiment have been modified for the purpose of improving and optimizing the signal-to-noise ratio.
- the apparatus and electronic processing means for the third embodiment are substantially the same as for the first preferred embodiment with additional optical means which reconfigure the interferometer of the first embodiment so that the ratio of the amplitudes of the reference and probe beams can be adjusted, optical elements of the third preferred embodiment performing like operations as like denoted elements in the first preferred embodiment and the electronic processing means of the third preferred embodiment performing like operations as like denoted electronic operations of first preferred embodiment.
- the ratio of the amplitudes of the reference and probe beams are adjusted by altering the transmission/reflection coefficients of beam splitters 100,
- the progenitor beams of reflected reference beam R32D undergo one transmission and one reflection at beam splitters 100 and 100a, respectively, while the progenitor beams of in-focus scattered probe beam P32D undergo one transmission at beam splitter 100a and one reflection and one transmission at beam splitter 100.
- the progenitor beams of reflected reference beam R32D and the in- focus scattered probe beam P32D do not receive identical treatment by beam splitters 100 and 100a as in the case of FIGS. la-j.
- the ratio of the amplitudes of the reflected reference beam R32D and the in- focus scattered probe beam P32D can be increased by increasing the transmission coefficient of beam splitter 100 and/or the reflection coefficient of beam splitter 100a.
- the third preferred embodiment of the present invention is an interferometer comprised of beam splitters 100, 100a, and 100b, object material 112, a reference mirror 120, and a detector 114.
- This configuration is known in the art as a form of a Michelson interferometer, and is shown as a simple illustration.
- Other forms of interferometers known in the art such as a polarized Michelson interferometer and as described in an article entitled "Differential Interferometer Arrangements for Distance and Angle Measurements: Principles, Advantages, and Applications," by Zanoni, ibid, may be incorporated into the apparatus of FIGS. 3a-j without significantly departing from the spirit and scope of the preferred third embodiment of the present invention.
- light source 10 is preferably a point source or a spatially incoherent source of radiation across surface of the source, preferably a laser or like source of coherent or partially coherent radiation, and preferably polarized.
- Light source 10 emits input beam 2 aligned with the subsystem 80 optical axis 3.
- light beam 2 enters focusing lens 6 and is focused at pinhole 8 in image plane 7.
- Phase shifter 14 is comprised of rectangular phase shifters 14-1,-2,-3,-4 which are located so that their respective optical axes are parallel to optical axis 3 of subsystem 80.
- the number of phase shifters may be any suitable number 2m , m being an integer.
- the example shown in FIG. 3b is for the case of m — 2 , the case of four phase shifters being sufficient to clearly show the relationship between the components of the apparatus of the present invention.
- phase shifters 14-1,-2,-3,-4 pass through phase shifters 14-1,-2,-3,-4, respectively, and emerge from phase shifter 14 as light beams 12B-1, -2, -3, -4, respectively, which comprise light beam 12B.
- Each of the phase shifters 14-2 and 14-4 introduce a phase shift of ⁇ radians more the phase shift introduced by each of the phase shifters 14-1 and 14-3, the phase shifts introduced by phase shifters 14-1 and 14-3 being the same.
- light beam 12B exits subsystem 80 and is partially transmitted by beam splitter 100a as light beam P12B comprised of light beams P12B-1, -2, -3 , -4.
- Light beam P12B enters subsystem 81a.
- FIG. 3c light beam P12B enters lens 26a and emerges as light beam P12C comprised of light beams P12C-1, -2, -3, -4.
- Lens 26a focuses light beam P12C to image point 18a in in-focus image plane 17a.
- Light beam P12C emerges from point image 18a as light beam P22 comprised of light beams P22-1, -2 , -3, -4.
- Light beam P22 enters lens 36a having an optical axis aligned with optical axis 3 of subsystem 81a.
- Light beam P22 emerges from lens 36a and exits subsystem 81a as collimated light beam P22A comprised of light beams P22A-l,-2,- 3,-4.
- light beam P22A is partially transmitted by beam splitter 100 as light beam P22B comprised of light beams P22B-1, -2, -3 , -4 and enters subsystem 82 shown in FIG. 3d.
- phase shifter 24 In FIG. 3d, light beam P22B impinges onto a phase shifter 24 comprised of elements 24-1,-2,-3,-4.
- Light beams P22B-1, -2 , -3, -4 pass through phase shifters 24-1,-2,-3,-4, respectively, and emerge as light beam P22C comprised of light beams P22C-l,-2,- 3,-4, respectively.
- the phase shifts introduced by phase shifters 24-1 and 24-3 are of equal values which are ⁇ radians more than the phase shift introduced by either phase shifter 24- 2 or 24-4, the phase shifts introduced by phase shifters 24-2 and 24-4 being of equal values.
- Light beam P22C passes through lens 46 as light beam P22D comprised of light beams P22D-l,-2,- 3,-4 which is focused to point image 28 in in-focus image plane 27 in object material 112.
- Optical axis of lens 46 is aligned with optical axis 3 of subsystem 82.
- light beam 12B is partially reflected by beam splitter 100a as light beam R12B comprised of light beams R12B- 1,-2,-3,-4.
- Light beam R12B enters subsystem 81b.
- light beam R12B enters lens 26b and emerges as light beam R12C comprised of light beams R12C-1, -2, -3 , -4.
- Lens 26b has an optical axis aligned with optical axis 3b of subsystem 81b.
- Lens 26b in conjunction with plane mirror 120b focuses light beam R12C to point image 18b in in-focus image plane 17b.
- Light beam R12C emerges from point image 18b as light beam R22 comprised of light beams R22-1, -2, -3, -4.
- Light beam R22 enters lens 36b having an optical axis aligned with optical axis 3c of subsystem 81b.
- Light beam R22 emerges from lens 36b and exits subsystem 81b as collimated light beam R22A comprised of light beams R22A-1, -2, -3, -4.
- phase shifter 34a contains the same number of elements, 2m , as phase shifter 14 and is shown in FIG. 3f with m — 2 .
- Light beam R22A passes through phase shifter 34a as lignt beam R22B which is then partially reflected as light beam R22C comprised of light beams R22C-1, -2, -3, -4.
- phase shifts introduced by phase shifters 34a-l and 34a-3 are of equal values which are ⁇ radians more than the phase shifts introduced by either phase shifter 34a-2 or 34a-4, the phase shifts introduced by phase shifters 34a-2 and 34a-4 being of equal values.
- Light beam R22C passes through lens 56a as light beam R22D comprised of light beams R22D-l,-2,- 3,-4.
- Light beam R22D is focused by lens 56a to point image 38 in in-focus image plane 37 on reference mirror 120.
- Optical axis of lens 56a is aligned with optical axis 3a of subsystem 83a.
- a portion of light beam P22D ( cf . FIG. 3d) is reflected and/or scattered by the object material at point image 28 as a plurality of light beams P32-1, -2, -3, -4 comprising light beam P32.
- Light beam P32 diverges from point image 28 in in- focus image plane 27 and enters lens 46.
- light beam P32 emerges from lens 46 as collimated light beam P32A comprised of light beams P32A-1, -2, -3, -4.
- phase shifters 24-1 and 24-3 are of equal values which are ⁇ radians more than the phase shifts introduced by either phase shifter 24-2 or 24-4, the phase shifts introduced by phase shifters 24-2 and 24-4 being of equal values.
- light beam R22D ( cf. FIG. 3f) is reflected by reference mirror 120 as light beam R32 comprised of light beams R32-1, -2, -3, -4.
- Light beam R32 diverges from point image 38 in in-focus image plane 37 and enters lens 56a. As shown in FIG. 3h, light beam R32 emerges from lens 56a as collimated light beam R32A comprised of light beams R32A-1, -2, -3, -4. Light beams R32A-1, -2 , -3, -4 are partially transmitted by beam splitter 100b with the partially transmitted beams subsequently passing through phase shifter 44 and then through phase shifters 34-4,- 3,-2-,-l, respectively, to emerge as light beams R32B-1, -2, -3 , - 4, respectively.
- the phase shift introduced by phase shifter 44 is controlled by signal 132 from computer 118.
- phase shifts introduced by phase shifters 34-1 and 34-3 are of equal values which are ⁇ radians more than the phase shifts introduced by either phase shifter 34-2 or 34-4, the phase shifts introduced by phase shifters 34-2 and 34-4 being of equal values.
- Light beams R32B-1, -2, -3, -4 comprise light beam R32B which exits subsystem 83a.
- light beam P32B is partially reflected by beam splitter 100 as light beam P32C which is comprised of light beams P32C-1, -2, -3, -4.
- Light beam P32C enters subsystem 84 shown in FIG. 3i, subsequently passes through lens 66, and emerges as light beam P32D comprised of light beams P32D-1, -2, -3 , -4.
- Light beam P32D is focused by lens 66 to point image 48 in in-focus image plane 47 on single pixel detector 114.
- Optical axis of lens 66 is aligned with subsystem optical axis 3a of cell 84.
- light beam R32B is partially transmitted by beam splitter 100 as light beam R32C which is comprised of light beams R32C-1, -2, -3 , -4.
- Light beam R32C subsequently enters subsystem 84 shown in FIG. 3j .
- light beam R32C passes through lens 66 and emerges as light beam R32D comprised of light beams R32D-1, -2, -3 , -4.
- Light beam R32D is focused by lens 66 to point image 48 in in-focus image plane 47 on single pixel detector 114.
- FIG. 3a-j The remainder of the third embodiment depicted in FIG. 3a-j is preferably the same as described in the description of FIGS. la-j and will not be described again.
- FIGS. 4a-d depict in schematic form a fourth embodiment of the instant invention in which the source subsystem 80a and the detector subsystem 84a are preferably configured for slit confocal microscopy.
- the source subsystem 80a and the detector subsystem 84a are preferably configured for slit confocal microscopy.
- Like reference numerals are used in FIGS. 4a-d for like elements previously described with reference to FIGS. 3a-j .
- the pinhole in the image plane 47 of the third embodiment is now preferably a linear array of detector pinholes aligned with the image of the linear array of source pinholes 8a in image plane 47 and the single pixel detector 114 of the third embodiment is now preferably a linear array detector 114a comprised of a linear array of pixels.
- the linear array of source pinholes 8a and source 10a are aligned perpendicular to the plane of FIG. 4b and in FIGS. 4c and 4d
- the linear array of detector pinholes and the linear array of detector pixels is aligned perpendicular to the plane of FIGS. 4c and 4d.
- FIGS. 5a-f there is shown an alternative fifth embodiment of the present invention in which the paths for the reference and probe beams of the first and third embodiments have been modified for the purpose of discriminating between the complex amplitude of an in-focus image and the complex amplitude of an out-of-focus image for images obtained from light transmitted through the object material nominally in the same direction as the direction of propagation of the probe beam.
- the fifth preferred embodiment of the present invention is an interferometer comprised of a beam splitters 100a and 100c, object material 112, folding mirrors
- FIGS. 5a-f This configuration is known in the art as a Mach-Zehnder interferometer, and is shown as a simple illustration. Other forms of the interferometer known in the art may be incorporated into the apparatus of FIGS. 5a-f without significantly departing from the spirit and scope of the preferred fifth embodiment of the present invention.
- FIG. 5b depicts in schematic form the embodiment of the subsystem 80b shown in FIG. 5a.
- light source 10 is preferably a point source or a spatially incoherent source of radiation across surface of the source, preferably a laser or like source of coherent or partially coherent radiation, and preferably polarized.
- Light source 10 emits input beam 2 aligned with the subsystem 80b optical axis 3. As shown in FIG. 5b, light beam 2 enters focusing lens 6 and is focused at pinhole 8 in image plane 7.
- Light beam 12 comprised of a plurality of light beams 12-1,-2,- 3,-4 diverges from the pinhole 8 and enter lens 16 having an optical axis aligned with subsystem 80b optical axis 3.
- Light beam 12 emerges from lens 16 as collimated light beam 12A comprised of light beams 12A-1, -2, -3 , -4 and exits subsystem 80b.
- light beam 12A exits subsystem 80b as light beam 12B and light beam 12B is partially transmitted by beam splitter 100a as light beam P12B comprised of light beams P12B- 1,-2,-3,-4.
- Light beam P12B enters subsystem 82a.
- light beam P12B enters lens 46a and emerges as light beam P12C comprised of light beams P12C-1, -2, -3 , -4.
- Lens 46a focuses light beam P12C to point image 48 in in-focus image plane 47 in object material 112.
- Optical axis of lens 46a is aligned with optical axis 3 of subsystem 82a.
- a portion of light beam P12C is transmitted by the object material 112 after passing through point image 48 as a plurality of light beams P22-1, -2, -3, -4 comprising light beam P22.
- Light beam P22 diverges from point image 48 in in-focus image plane 47 and enters lens 46b.
- light beam P22 emerges from lens 46b as collimated light beam P32 comprised of light beams P32-1, -2, -3, -4.
- Light beam P32 exits subsystem 82a.
- light beam 12B is partially reflected by beam splitter 100a as light beam R12B comprised of light beams R12B- 1,-2,-3,-4.
- Light beam R12B enters subsystem 81b.
- light beam R12B enters lens 26b and emerges as light beam R12C comprised of light beams R12C-1, -2, -3 , -4.
- Lens 26b has an optical axis aligned with optical axis 3b of subsystem 81b.
- Lens 26b in conjunction with plane mirror 120b focuses light beam R12C to point image 18b in in-focus image plane 17b.
- Light beam R12C emerges from point image 18b as light beam R32 comprised of light beams R32-1, -2, -3 , -4.
- Light beam R32 enters lens 36b having an optical axis aligned with optical axis 3c of subsystem 81b.
- Light beam R32 emerges from lens 36b and exits subsystem 81b as collimated light beam R32A comprised of light beams R32A-1, -2, -3, -4.
- light beam P32 is reflected by mirror 120c and enters subsection 85 as light beam P32A.
- light beam enters subsection 85 and impinges of phase shifter 24a.
- Light beams P32A-1, -2, -3 , -4 pass through phase shifters 24a-l, -2, -3, -4, respectively, and emerge as light beams P32B-1, -2 , -3 , -4, respectively.
- Light beams P32B-1, -2 , -3, - 4 comprise light beam P32B.
- phase shifts introduced by phase shifters 24a-l and 24a-3 are of equal values which are ⁇ radians more than the phase shifts introduced by either phase shifter 24a-2 or 24a-4, the phase shifts introduced by phase shifters 24a-2 and 24a-4 being of equal values.
- light beam P32B is partially reflected by beam splitter 100c as light beam P32C comprised of light beams P32C-1, -2, -3, -4.
- Light beam P32C passes through lens 66 and emerges as light beam P32D comprised of light beams P32D-1, -2, -3, -4.
- Light beam P32D is focused by lens 66 to point image 48 in in-focus image plane 47 on single pixel detector 114.
- Optical axis of lens 66 is aligned with subsystem optical axis 3c of cell 85.
- light beam R32A enters subsystem 85.
- light beams R32A-1, -2 , -3, -4 pass first through phase shifters 34-1,-2,-3,-4, respectively, and then through phase shifter 44 to emerge as light beams R32B-1, -2, -3, -4, respectively.
- Light beams R32B-1,- 2,-3,-4 comprise light beam R32B.
- the phase shift introduced by phase shifter 44 is controlled by signal 132 from computer 118.
- phase shifts introduced by phase shifters 34-1 and 34-3 are of equal values which are ⁇ radians more than the phase shifts introduced by either phase shifter 34-2 or 34-4, the phase shifts introduced by phase shifters 34-2 and 34-4 being of equal values.
- Light beam R32B is partially transmitted by beam splitter 100c as light beam R32C comprised of light beams R32C- 1,-2,-3,-4.
- Light beam R32C passes through lens 66 and emerges as light beam R32D comprised of light beams R32D-1, -2, -3, -4.
- Light beam R32D is focused by lens 66 to point image 48 in in- focus image plane 47 on single pixel detector 114.
- the remainder of the fifth embodiment depicted in FIG. 5a-f is preferably the same as described in the description of FIGS. la-j and FIGS. 3a-j and will not be described again.
- FIGS. 6a-d depict in schematic form a sixth embodiment of the instant invention in which the source subsystem 80c and the detector subsystem 85a are preferably configured for slit confocal microscopy.
- the source subsystem 80c and the detector subsystem 85a are preferably configured for slit confocal microscopy.
- Like reference numerals are used in FIGS. 6a-d for like elements previously described with reference to FIGS. 5a-f .
- the pinhole in the image plane 47 of the fifth embodiment is now preferably a linear array of detector pinholes aligned with the image of the linear array of source pinholes 8a in image plane 47 and the single pixel detector 114 of the fifth embodiment is now preferably a linear array detector 114a comprised of a linear array of pixels.
- the linear array of source pinholes 8a and source 10a are aligned perpendicular to the plane of FIG. 6b and in FIGS. 6c and 6d
- the linear array of detector pinholes and the linear array of detector pixels is aligned perpendicular to the plane of FIGS. 6c and 6d.
- FIGS. 6a- d The remainder of the sixth embodiment depicted in FIGS. 6a- d is preferably the same as described for the fifth preferred embodiment in the description of FIGS. 5a-f and will not be described again.
- phase shifters 14, 24, 24a, 34, and 34a may be apodized in order to alter the properties of the apparatus of the present invention vis-a-vis the magnitude of reduction of signals from out-of- focus images and the spatial resolving power without departing from the spirit and scope of the present invention. It will also be appreciated by those skilled in the art that the function of the phase shifters 14, 24, 24a, 34, and 34a may be achieved by other combinations of phase shifters or be configured with elements comprised of sections of a set of concentric annuli or other geometric patterns without departing from the spirit and scope of the present invention. Phase shifters 14, 24, 24a, 34, 34a, and 44 may be of the electro-optical type or of the dispersive optical element type.
- phase shifts described as being introduced by phase shifter 44 may alternatively be produced by making displacements of mirrors such as, for example, reference mirror 120 in the direction of the subsystem optical axis 3a of subsystems 83 and 83a.
- phase shifters 14, 24, 24a, 34, 34a, and 44 are not dependent on wavelength. It is possible to meet broadband phase shifter requirements by appropriately designing phase shifters 14, 24, 24a, 34, 34a, and 44 as types such as ' disclosed by H. A. Hill, J. W. Figoski, and P. T. Ballard in U.S. Pat. No. 4,213,706 issued Jul . , 1980 and entitled "Background Compensating Interferometer" and by H. A. Hill, J. W. Figoski, and P. T. Ballard in U.S. Pat. No.
- the apparatus described in the preferred embodiments are all examples of either a pinhole confocal interference microscopy system or a slit confocal interference microscopy system.
- the background reduction capacity of a confocal microscopy system is one of its most important attributes and results from the strong optical sectioning property of confocal microscopy. This is of a completely different nature from the restricted depth of field in conventional microscopy, the difference being that in a conventional microscope out-of-focus information is merely blurred, whilst in the confocal system it is actually detected much less strongly: light scattered at some place axially separated from the focal plane is defocused at the detector plane and hence fails to pass efficiently through a mask placed there [cf. C. J. R. Sheppard and C. J. Cogswell, "Three-dimensional Imaging In Confocal Microscopy” , Confocal Microscopy, edited by T. Wilson, (Academic Press, London), 143- 169 (1990) ] .
- FIGS, la-j, 2a-d, 3a-j , 4a-d, 5a-f, and 6a-d An unusual characteristic of the confocal interference microscope of the present invention in FIGS, la-j, 2a-d, 3a-j , 4a-d, 5a-f, and 6a-d is that the reflected or transmitted reference beam and the scattered or transmitted probe beam are both substantially altered at the in-focus image point 48 by pupil function modifications whereas the portion of the out-of- focus beam at in-focus image point 48 is substantially unaltered.
- Confocal interference microscopy systems are known in the art as a means to improve optical sectioning for the purpose of obtaining two- and three- dimensional images of an object and pupil function modification schemes for microscopes [ cf. M. Born and E.
- Wilson Optics Lett . , 3, 115-117 (1978); C. J. R. Sheppard, D. K. Hamilton, and I. J. Cox, Froc. R . Soc . Lond. , A 387, 171-186 (1983)] and thus form three dimensional images.
- lens 1 of FIG. 7 is the equivalent to the combination of lenses 16 and 26
- lens 2 of FIG. 7 is the equivalent to the combination of lenses 36 and 46
- lens 3 of FIG. 7 is the equivalent to the combination of lenses 46 and 66.
- y, n( ⁇ >y:>z ⁇ ) ⁇ ty > ( 2 .
- n ⁇ x',y',z' is the refractive index at position (x', y',z') .
- ⁇ , , 7 , and W ⁇ are the impulse response function, the pupil function, and the wave aberration function [ cf. Refs . 10-12 in M. Gu and C. J. R. Sheppard, Appl . Opt . , 31(14), 2541-2549, (1992)], respectively, for the i th equivalent lens; and j is
- the impulse response function is the amplitude in the image plane in response to a point-source object.
- the functions of the phase shifters 14, 24, 24a, 34, 34a and 44 are incorporated into the appropriate pupil functions 7) .
- the role of any apodization of the phase shifters 14, 24, 24a, 34, 34a and 44 are also incorporated into the appropriate 7) .
- the three-dimensional object may be characterized by a scattering distribution t(v 0 ) [ cf . C. J. R.
- the attenuation function ⁇ (v 0 ) accounting for the attenuation of the radiation in the object must also be included for both the incident radiation on the object and the reflected/scattered radiation by the object.
- the amplitude of the in-focus scattered probe beam U 5 in the image space 47A is thus given by
- R, and 7j are the reflection and transmission coefficients, respectively, for the beam splitter 100.
- z 0 has been replaced by z_
- a' and d 0 are the width and the center to center distance, respectively, of the elements in phase shifters 14, 24, 24a, 34, and 34a and sine x ⁇ (sin x)/x .
- the w, dependence has been suppressed since it is not relevant in Level 1 discrimination to the reduction of the background from out-of- focus images.
- the amplitude of the out-of-focus beam U fl in the detector in-focus image plane 47 can be express in terms of the Fresnel internals C(z) and S(z) which are defined as
- U * denotes the complex conjugate of U and the integration is over intervals centered about the position where U ⁇ is antisymmetric in x 2 for Level 1 discrimination and in both x 3 and y 3 for Level 2 discrimination.
- a very significant feature of the properties of apparatus which embodies the present invention is that the enhanced reduction of the interference term is effective for each independent volume element of the source of out-of-focus images. Therefore, the reduction leads to both a reduction in the statistical error as well as an enhanced reduction in the systematic error produced by the background from out-of-focus images .
- Eqs. (26a) and (26b), Eqs. (27a) and (27b), and Eqs. (29a) and (29b) is the following: it is possible with the invention disclosed herein to achieve from a set of four intensity measurements the components of the complex scattering amplitude such that for each independent position in the object, the statistical error for each of the components of the inferred complex scattering amplitude is typically within a factor of (3/2) 2 of the limiting statistical error fixed by the statistics of the complex scattering amplitude itself, and that the referred to statistical error can be achieved with lower operating power levels of the source and lower required dynamic range capacity in the signal processing electronics in relation to prior art confocal interference microscopes.
- the term independent position is used to mean that the associated sets of four measured intensities are statistically independent sets. It may be possible to achieve the condition expressed by Eq. (28) for the first and second embodiments illustrated in FIGS, la-j and FIGS. 2a-d by reducing the transmission of phase shifter 24 so as to attenuate simultaneously the scattered probe beam and the out-of-focus image beam at the image plane 47. In order to obtain a given signal-to-noise ratio, this attenuation procedure may require the increase of the strength of the light source 10 as the attenuation at phase shifter 24 is increased.
- the alternative third and fourth embodiments of the invention illustrated in FIGS. 3a-j and FIGS. 4a-d permits the condition given by Eq.
- the light source 10 or 10a may in general be operated at lower power levels relative to that required by the above described attenuation procedure based on the reduction of transmission of beam splitter 24.
- Eqs. (24a) and (24b) can be used in conjunction with measured values of I_ — I_ and 7 3 -7 4 to obtain measurements of the real and imaginary parts of the phasor U 5 as long as
- the computer processing required to perform the inversion of the respective integral equations to obtain U s decreases when the jj (U ⁇ U ⁇ * + U R * U B ) dx 3 dy 3 and jj (U ⁇ U ⁇ * - U R ' ⁇ J B ) dx 3 dy 3 terms are reduced such as in apparatus which embodies the present invention.
- the rate of decrease in the required computer processing is faster then the rate of reduction of the jj_(V R V B ' +V R "V B ) dx 3 dy 3 and JJ p (U ⁇ U ⁇ * - V R ' B ) dx 3 dy 3 terms.
- the integral equations corresponding to Eqs. (24a) and (24b) are nonlinear integral equations: they are integral equations that are second order in V s .
- Nonlinear integral equations require in general considerably more sophistication in regards to the computer hardware and software for their solution than do linear integral equations.
- JJ (U ⁇ U ⁇ * — XJ R * ⁇ J B ' ) dx 3 dy_ terms represents an important feature of the invention in relation to prior art pinhole confocal microscopy.
- One of the significant features of the invention is that the enhanced reduction of the effects of background from out-of- focus images is operative when source 10 is a broadband source. From system properties such as exhibited in Eq. (14) , it is evident that a high sensitivity for U s (v 3 ) given by Eq. (12) is maintained for the in-focus image as long as the phase ( ⁇ -l ⁇ ) meets the condition that ⁇ ⁇ ( ⁇ 3 - ⁇ ) ⁇ - ( 31 )
- apparatus embodying the present invention is affective for point like sources with no intrinsic restriction on the range of values for x ⁇ and y x .
- Another significant feature of the invention disclosed herein is that the enhanced reduction of the effects of background from out-of-focus images can be operative when observing through a turbulent medium.
- the impulse response function h A M for observing through a turbulent medium is
- h A is the impulse response function for the apparatus when observing through non turbulent medium
- h M is the impulse response function for the turbulent medium
- * denotes the convolution of h A and h M .
- the Fourier transform of h A *h M is
- the impulse response function h M is very well represented by a Gaussian distribution
- the tomographic imaging system embodying the present invention it is recognized that for a reference beam amplitude of arbitrary spatial properties, the interference term between the amplitudes of the background light (i.e., the out-of-focus return probe beam) and the reference beam may dominate generation of undesired systematic errors and be important in generation of undesired statistical errors.
- the interference term between the amplitudes of the background light and the reference beam is reduced in the above embodiments of the invention because of the antisymmetric spatial properties produced in the reference beam by phase shifting.
- the amplitude of the reference beam and the interference term between the reference beam and the in-focus return probe beam are correlated.
- the reference beam is detected as the square of the amplitude of the reference beam.
- the in-focus return probe beam is detected as the interference term between the return reference beam and the in-focus return probe beam, i.e., the amplitude of the in-focus return probe beam multiplied by the amplitude of the reference beam.
- the detected reference beam and the detected return probe beam therefore are correlated, because the amplitude of the reference beam is present in each.
- optical elements and detectors may be incorporated into one of the disclosed embodiments of the present invention.
- polarizing beam splitters alternatively may be used and or used with additional phase shifting elements to alter the properties of the radiation used to probe the object material.
- a further example would be the addition of a detector to monitor the intensity of the light source.
- phase shifter 34 could be omitted for example in FIGS, la-j, in which case the image of point light source 8 produced at image point 38 in the in-focus image plane 37 will be different than described above although the image of point light source 8 produced by the reflected reference beam at image point 48 in the in-focus image plane 47 will not be altered substantially from that described above. Nonetheless, the above described cancellation of out-of-focus images would be achieved.
- phase shifter 34 could be omitted in FIGS. 2a-d and phase shifters 34 and 34a could be omitted in FIGS. 3a-j and 4a-d.
- phase shifter elements of phase shifters 14, 24, 24a, 34, and 34a may be different from that described above and/or apodized as long as the spatial distribution of the amplitude of the reflected reference beam in the single pixel detector plane produces a substantially spatially antisymmetric distribution.
- the image data produced by the single pixel detector must be processed slightly differently for the above described embodiments of the invention to produce the desired tomographic image of the object material 112.
- the interferometers of the embodiments described above could be of the polarizing type, for example for the purpose of probing the object material 112 with polarized light or for increasing the throughput of light through the interferometer to the single or multipixel detector.
- an additional optical element such as a polarizing beam splitter will need to be added to the apparatus described above for the purpose of mixing the reflected reference beam and the scattered probe beam at the single or multipixel detector.
Abstract
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EP98905982A EP1012535A1 (en) | 1997-01-28 | 1998-01-22 | Background compensation for confocal interference microscopy |
JP53470998A JP4229472B2 (en) | 1997-01-28 | 1998-01-22 | Background compensation for confocal interference microscopy |
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US08/789,885 | 1997-01-28 | ||
US08/789,885 US5760901A (en) | 1997-01-28 | 1997-01-28 | Method and apparatus for confocal interference microscopy with background amplitude reduction and compensation |
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EP (1) | EP1012535A1 (en) |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
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Families Citing this family (253)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5987189A (en) * | 1996-12-20 | 1999-11-16 | Wyko Corporation | Method of combining multiple sets of overlapping surface-profile interferometric data to produce a continuous composite map |
US5760901A (en) * | 1997-01-28 | 1998-06-02 | Zetetic Institute | Method and apparatus for confocal interference microscopy with background amplitude reduction and compensation |
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US6388788B1 (en) | 1998-03-16 | 2002-05-14 | Praelux, Inc. | Method and apparatus for screening chemical compounds |
US20030036855A1 (en) * | 1998-03-16 | 2003-02-20 | Praelux Incorporated, A Corporation Of New Jersey | Method and apparatus for screening chemical compounds |
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US6690469B1 (en) * | 1998-09-18 | 2004-02-10 | Hitachi, Ltd. | Method and apparatus for observing and inspecting defects |
US5975697A (en) * | 1998-11-25 | 1999-11-02 | Oti Ophthalmic Technologies, Inc. | Optical mapping apparatus with adjustable depth resolution |
US8005314B2 (en) * | 2005-12-09 | 2011-08-23 | Amnis Corporation | Extended depth of field imaging for high speed object analysis |
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US6546272B1 (en) | 1999-06-24 | 2003-04-08 | Mackinnon Nicholas B. | Apparatus for in vivo imaging of the respiratory tract and other internal organs |
US6606159B1 (en) | 1999-08-02 | 2003-08-12 | Zetetic Institute | Optical storage system based on scanning interferometric near-field confocal microscopy |
JP2003506741A (en) * | 1999-08-02 | 2003-02-18 | ゼテティック・インスティチュート | Scanning interferometer near-field confocal microscope |
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US6618152B2 (en) * | 2000-05-09 | 2003-09-09 | Fuji Photo Film Co., Ltd. | Optical coherence tomography apparatus using optical-waveguide structure which reduces pulse width of low-coherence light |
JP2001351842A (en) * | 2000-06-05 | 2001-12-21 | Canon Inc | Position detection method, position detection device, aligner, device manufacturing method, semiconductor manufacturing factory and maintenance method of aligner |
US20040224421A1 (en) * | 2000-06-15 | 2004-11-11 | Deweerd Herman | Bi-directional scanning method |
WO2002010829A2 (en) | 2000-07-27 | 2002-02-07 | Zetetic Institute | Multiple-source arrays with optical transmission enhanced by resonant cavities |
WO2002010828A2 (en) | 2000-07-27 | 2002-02-07 | Zetetic Institute | Control of position and orientation of sub-wavelength aperture array in near-field microscopy |
US6775009B2 (en) | 2000-07-27 | 2004-08-10 | Zetetic Institute | Differential interferometric scanning near-field confocal microscopy |
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EP1432960A2 (en) | 2000-09-04 | 2004-06-30 | Forskningscenter Riso | Optical amplification in coherence reflectometry |
JP4241038B2 (en) * | 2000-10-30 | 2009-03-18 | ザ ジェネラル ホスピタル コーポレーション | Optical method and system for tissue analysis |
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US6909509B2 (en) * | 2001-02-20 | 2005-06-21 | Zygo Corporation | Optical surface profiling systems |
US20060023219A1 (en) * | 2001-03-28 | 2006-02-02 | Meyer Michael G | Optical tomography of small objects using parallel ray illumination and post-specimen optical magnification |
US7907765B2 (en) | 2001-03-28 | 2011-03-15 | University Of Washington | Focal plane tracking for optical microtomography |
US6944322B2 (en) | 2001-03-28 | 2005-09-13 | Visiongate, Inc. | Optical tomography of small objects using parallel ray illumination and post-specimen optical magnification |
EP2333523B1 (en) | 2001-04-30 | 2020-04-08 | The General Hospital Corporation | Method and apparatus for improving image clarity and sensitivity in optical coherence tomography using dynamic feedback to control focal properties and coherence gating |
US7865231B2 (en) | 2001-05-01 | 2011-01-04 | The General Hospital Corporation | Method and apparatus for determination of atherosclerotic plaque type by measurement of tissue optical properties |
US20030045798A1 (en) * | 2001-09-04 | 2003-03-06 | Richard Hular | Multisensor probe for tissue identification |
WO2003060423A2 (en) * | 2002-01-11 | 2003-07-24 | The General Hospital Corporation | Apparatus for low coherence ranging |
US7355716B2 (en) | 2002-01-24 | 2008-04-08 | The General Hospital Corporation | Apparatus and method for ranging and noise reduction of low coherence interferometry LCI and optical coherence tomography OCT signals by parallel detection of spectral bands |
US6961291B2 (en) * | 2002-04-03 | 2005-11-01 | Plasmon Lms, Inc. | System for enhanced astigmatic focus signal detection |
US7738945B2 (en) * | 2002-04-19 | 2010-06-15 | University Of Washington | Method and apparatus for pseudo-projection formation for optical tomography |
US7197355B2 (en) | 2002-04-19 | 2007-03-27 | Visiongate, Inc. | Variable-motion optical tomography of small objects |
US7811825B2 (en) * | 2002-04-19 | 2010-10-12 | University Of Washington | System and method for processing specimens and images for optical tomography |
US20050085708A1 (en) * | 2002-04-19 | 2005-04-21 | University Of Washington | System and method for preparation of cells for 3D image acquisition |
US7260253B2 (en) | 2002-04-19 | 2007-08-21 | Visiongate, Inc. | Method for correction of relative object-detector motion between successive views |
DE10301416B3 (en) * | 2003-01-16 | 2004-07-15 | Medizinisches Laserzentrum Lübeck GmbH | Contactless temperature monitoring method using evaluation of interference pattern obtained by reflection of partial beams from different depths within sample |
US7623908B2 (en) * | 2003-01-24 | 2009-11-24 | The Board Of Trustees Of The University Of Illinois | Nonlinear interferometric vibrational imaging |
US8054468B2 (en) | 2003-01-24 | 2011-11-08 | The General Hospital Corporation | Apparatus and method for ranging and noise reduction of low coherence interferometry LCI and optical coherence tomography OCT signals by parallel detection of spectral bands |
WO2004088361A2 (en) | 2003-03-31 | 2004-10-14 | The General Hospital Corporation | Speckle reduction in optical coherence tomography by path length encoded angular compounding |
EP2319405B1 (en) | 2003-01-24 | 2013-09-18 | The General Hospital Corporation | System and method for identifying tissue using low-coherence interferometry |
EP1588119A4 (en) * | 2003-01-27 | 2007-03-07 | Zetetic Inst | Apparatus and method for joint measurements of conjugated quadratures of fields of reflected/scattered and transmitted beams by an object in interferometry |
US7084983B2 (en) * | 2003-01-27 | 2006-08-01 | Zetetic Institute | Interferometric confocal microscopy incorporating a pinhole array beam-splitter |
JP2006516762A (en) * | 2003-01-27 | 2006-07-06 | ゼテテック インスティテュート | Leaky sandwiched waveguide mode used in interference confocal microscopy to measure trench properties |
KR20050114615A (en) * | 2003-02-04 | 2005-12-06 | 제테틱 인스티튜트 | Compensation for effects of mismatch in indices of refraction at a substrate-medium interface in non-confocal, confocal, and interferometric confocal microscopy |
WO2004072688A2 (en) * | 2003-02-07 | 2004-08-26 | Zetetic Institute | Multiple-source arrays fed by guided-wave structures and resonant guided-wave structure cavities |
WO2004072695A2 (en) * | 2003-02-13 | 2004-08-26 | Zetetic Institute | Transverse differential interferometric confocal microscopy |
JP2006518487A (en) * | 2003-02-19 | 2006-08-10 | ゼテテック インスティテュート | Vertical differential interference confocal microscope |
JP2006518488A (en) * | 2003-02-19 | 2006-08-10 | ゼテテック インスティテュート | Method and apparatus for using dark field interference confocal microscope |
WO2004073501A2 (en) * | 2003-02-20 | 2004-09-02 | Gutin Mikhail | Optical coherence tomography with 3d coherence scanning |
WO2004090465A2 (en) * | 2003-04-01 | 2004-10-21 | Zetetic Institute | Apparatus and method for joint measurement of fields of scattered/reflected or transmitted orthogonally polarized beams by an object in interferometry |
US7054077B2 (en) | 2003-04-01 | 2006-05-30 | Zetetic Institute | Method for constructing a catadioptric lens system |
JP2006522338A (en) * | 2003-04-03 | 2006-09-28 | ゼテテック インスティテュート | Apparatus and method for field measurement of backscattered and forward scattered / reflected beams by interferometric objects |
WO2005008334A2 (en) | 2003-07-07 | 2005-01-27 | Zetetic Institute | Apparatus and method for high speed scan for detection and measurement of properties of sub-wavelength defects and artifacts in semiconductor and mask metrology |
WO2005008214A2 (en) * | 2003-07-07 | 2005-01-27 | Zetetic Institute | Apparatus and method for ellipsometric measurements with high spatial resolution |
US7355722B2 (en) * | 2003-09-10 | 2008-04-08 | Zetetic Institute | Catoptric and catadioptric imaging systems with adaptive catoptric surfaces |
US20050111007A1 (en) * | 2003-09-26 | 2005-05-26 | Zetetic Institute | Catoptric and catadioptric imaging system with pellicle and aperture-array beam-splitters and non-adaptive and adaptive catoptric surfaces |
US7312877B2 (en) * | 2003-10-01 | 2007-12-25 | Zetetic Institute | Method and apparatus for enhanced resolution of high spatial frequency components of images using standing wave beams in non-interferometric and interferometric microscopy |
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TW200538758A (en) * | 2004-04-28 | 2005-12-01 | Olympus Corp | Laser-light-concentrating optical system |
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US7345771B2 (en) * | 2004-05-06 | 2008-03-18 | Zetetic Institute | Apparatus and method for measurement of critical dimensions of features and detection of defects in UV, VUV, and EUV lithography masks |
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WO2006014392A1 (en) | 2004-07-02 | 2006-02-09 | The General Hospital Corporation | Endoscopic imaging probe comprising dual clad fibre |
US8081316B2 (en) | 2004-08-06 | 2011-12-20 | The General Hospital Corporation | Process, system and software arrangement for determining at least one location in a sample using an optical coherence tomography |
US7161680B2 (en) * | 2004-08-16 | 2007-01-09 | Zetetic Institute | Apparatus and method for joint and time delayed measurements of components of conjugated quadratures of fields of reflected/scattered and transmitted/scattered beams by an object in interferometry |
WO2006023612A2 (en) * | 2004-08-19 | 2006-03-02 | Zetetic Institute | Sub-nanometer overlay, critical dimension, and lithography tool projection optic metrology systems based on measurement of exposure induced changes in photoresist on wafers |
US8208995B2 (en) | 2004-08-24 | 2012-06-26 | The General Hospital Corporation | Method and apparatus for imaging of vessel segments |
WO2006024014A2 (en) | 2004-08-24 | 2006-03-02 | The General Hospital Corporation | Process, system and software arrangement for measuring a mechanical strain and elastic properties of a sample |
US7365859B2 (en) * | 2004-09-10 | 2008-04-29 | The General Hospital Corporation | System and method for optical coherence imaging |
WO2006034065A2 (en) * | 2004-09-20 | 2006-03-30 | Zetetic Institute | Catoptric imaging systems comprising pellicle and/or aperture-array beam-splitters and non-adaptive and /or adaptive catoptric surfaces |
EP2329759B1 (en) | 2004-09-29 | 2014-03-12 | The General Hospital Corporation | System and method for optical coherence imaging |
US6991738B1 (en) | 2004-10-13 | 2006-01-31 | University Of Washington | Flow-through drum centrifuge |
US20060096358A1 (en) * | 2004-10-28 | 2006-05-11 | University Of Washington | Optical projection tomography microscope |
JP5175101B2 (en) * | 2004-10-29 | 2013-04-03 | ザ ジェネラル ホスピタル コーポレイション | System and method for performing Jones matrix based analysis to measure unpolarized polarization parameters using polarization sensitive optical coherence tomography |
US7494809B2 (en) * | 2004-11-09 | 2009-02-24 | Visiongate, Inc. | Automated cell sample enrichment preparation method |
US7472576B1 (en) | 2004-11-17 | 2009-01-06 | State Of Oregon Acting By And Through The State Board Of Higher Education On Behalf Of Portland State University | Nanometrology device standards for scanning probe microscopes and processes for their fabrication and use |
US7995210B2 (en) | 2004-11-24 | 2011-08-09 | The General Hospital Corporation | Devices and arrangements for performing coherence range imaging using a common path interferometer |
JP2008521516A (en) | 2004-11-29 | 2008-06-26 | ザ ジェネラル ホスピタル コーポレイション | Configuration, apparatus, endoscope, catheter, and method for performing optical image generation by simultaneously illuminating and detecting multiple points on a sample |
US7586618B2 (en) * | 2005-02-28 | 2009-09-08 | The Board Of Trustees Of The University Of Illinois | Distinguishing non-resonant four-wave-mixing noise in coherent stokes and anti-stokes Raman scattering |
EP1869399A2 (en) * | 2005-04-11 | 2007-12-26 | Zetetic Institute | Apparatus and method for in situ and ex situ measurement of spatial impulse response of an optical system using phase-shifting point-diffraction interferometry |
US7725169B2 (en) * | 2005-04-15 | 2010-05-25 | The Board Of Trustees Of The University Of Illinois | Contrast enhanced spectroscopic optical coherence tomography |
EP2325803A1 (en) | 2005-04-28 | 2011-05-25 | The General Hospital Corporation | Evaluating optical coherence tomography information for an anatomical structure |
US7428058B2 (en) * | 2005-05-18 | 2008-09-23 | Zetetic Institute | Apparatus and method for in situ and ex situ measurements of optical system flare |
EP1887926B1 (en) | 2005-05-31 | 2014-07-30 | The General Hospital Corporation | System and method which use spectral encoding heterodyne interferometry techniques for imaging |
EP1896875A2 (en) * | 2005-06-14 | 2008-03-12 | L-3 Communications Security and Detection Systems, Inc. | Inspection system with material identification |
WO2007019548A2 (en) * | 2005-08-08 | 2007-02-15 | Zetetic Institute | Apparatus and methods for reduction and compensation of effects of vibrations and of environmental effects in wavefront interferometry |
ES2354287T3 (en) | 2005-08-09 | 2011-03-11 | The General Hospital Corporation | APPARATUS AND METHOD FOR PERFORMING A DEMODULATION IN QUADRATURE BY POLARIZATION IN OPTICAL COHERENCE TOMOGRAPHY. |
US7990829B2 (en) * | 2005-08-24 | 2011-08-02 | Fujifilm Corporation | Optical recording method, optical recording apparatus, optical recording medium, and optical reproducing method |
WO2007025147A2 (en) * | 2005-08-26 | 2007-03-01 | Zetetic Institute | Apparatus and method for measurement and compensation of atmospheric turbulence effects in wavefront interferometry |
WO2007030741A2 (en) * | 2005-09-09 | 2007-03-15 | Trustees Of Boston University | Imaging system using dynamic speckle illumination |
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US7889348B2 (en) | 2005-10-14 | 2011-02-15 | The General Hospital Corporation | Arrangements and methods for facilitating photoluminescence imaging |
WO2007059249A2 (en) * | 2005-11-15 | 2007-05-24 | Zetetic Institute | Interferometer with coherent artifact reduction plus vibration and enviromental compensation |
EP1971848B1 (en) | 2006-01-10 | 2019-12-04 | The General Hospital Corporation | Systems and methods for generating data based on one or more spectrally-encoded endoscopy techniques |
US8145018B2 (en) | 2006-01-19 | 2012-03-27 | The General Hospital Corporation | Apparatus for obtaining information for a structure using spectrally-encoded endoscopy techniques and methods for producing one or more optical arrangements |
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JP2008135125A (en) * | 2006-11-29 | 2008-06-12 | Ricoh Co Ltd | Optical head, optical disk device, and information processing device |
US7949019B2 (en) | 2007-01-19 | 2011-05-24 | The General Hospital | Wavelength tuning source based on a rotatable reflector |
US7911621B2 (en) | 2007-01-19 | 2011-03-22 | The General Hospital Corporation | Apparatus and method for controlling ranging depth in optical frequency domain imaging |
WO2008104913A1 (en) * | 2007-02-26 | 2008-09-04 | Koninklijke Philips Electronics N.V. | Method and device for optical analysis of a tissue |
EP2602651A3 (en) | 2007-03-23 | 2014-08-27 | The General Hospital Corporation | Methods, arrangements and apparatus for utilizing a wavelength-swept laser using angular scanning and dispersion procedures |
US8217937B2 (en) * | 2007-03-28 | 2012-07-10 | The Aerospace Corporation | Isosurfacial three-dimensional imaging system and method |
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US7835561B2 (en) | 2007-05-18 | 2010-11-16 | Visiongate, Inc. | Method for image processing and reconstruction of images for optical tomography |
US9596993B2 (en) | 2007-07-12 | 2017-03-21 | Volcano Corporation | Automatic calibration systems and methods of use |
WO2009009799A1 (en) | 2007-07-12 | 2009-01-15 | Volcano Corporation | Catheter for in vivo imaging |
WO2009009802A1 (en) | 2007-07-12 | 2009-01-15 | Volcano Corporation | Oct-ivus catheter for concurrent luminal imaging |
JP5917803B2 (en) | 2007-07-31 | 2016-05-18 | ザ ジェネラル ホスピタル コーポレイション | System and method for emitting a beam scanning pattern for fast Doppler optical frequency domain imaging |
EP2191254B1 (en) | 2007-08-31 | 2017-07-19 | The General Hospital Corporation | System and method for self-interference fluorescence microscopy, and computer-accessible medium associated therewith |
US9347765B2 (en) * | 2007-10-05 | 2016-05-24 | Volcano Corporation | Real time SD-OCT with distributed acquisition and processing |
US20090131801A1 (en) * | 2007-10-12 | 2009-05-21 | The General Hospital Corporation | Systems and processes for optical imaging of luminal anatomic structures |
US7787112B2 (en) * | 2007-10-22 | 2010-08-31 | Visiongate, Inc. | Depth of field extension for optical tomography |
WO2009059034A1 (en) | 2007-10-30 | 2009-05-07 | The General Hospital Corporation | System and method for cladding mode detection |
US8139846B2 (en) * | 2007-11-05 | 2012-03-20 | University Of Southern California | Verification of integrated circuits against malicious circuit insertions and modifications using non-destructive X-ray microscopy |
US8983580B2 (en) | 2008-01-18 | 2015-03-17 | The Board Of Trustees Of The University Of Illinois | Low-coherence interferometry and optical coherence tomography for image-guided surgical treatment of solid tumors |
US7751057B2 (en) | 2008-01-18 | 2010-07-06 | The Board Of Trustees Of The University Of Illinois | Magnetomotive optical coherence tomography |
US8115934B2 (en) | 2008-01-18 | 2012-02-14 | The Board Of Trustees Of The University Of Illinois | Device and method for imaging the ear using optical coherence tomography |
US9332942B2 (en) | 2008-01-28 | 2016-05-10 | The General Hospital Corporation | Systems, processes and computer-accessible medium for providing hybrid flourescence and optical coherence tomography imaging |
US11123047B2 (en) | 2008-01-28 | 2021-09-21 | The General Hospital Corporation | Hybrid systems and methods for multi-modal acquisition of intravascular imaging data and counteracting the effects of signal absorption in blood |
US8143600B2 (en) | 2008-02-18 | 2012-03-27 | Visiongate, Inc. | 3D imaging of live cells with ultraviolet radiation |
US8090183B2 (en) * | 2009-03-12 | 2012-01-03 | Visiongate, Inc. | Pattern noise correction for pseudo projections |
EP2274572A4 (en) | 2008-05-07 | 2013-08-28 | Gen Hospital Corp | System, method and computer-accessible medium for tracking vessel motion during three-dimensional coronary artery microscopy |
WO2009155536A2 (en) | 2008-06-20 | 2009-12-23 | The General Hospital Corporation | Fused fiber optic coupler arrangement and method for use thereof |
WO2010009136A2 (en) | 2008-07-14 | 2010-01-21 | The General Hospital Corporation | Apparatus and methods for color endoscopy |
JP5731394B2 (en) | 2008-12-10 | 2015-06-10 | ザ ジェネラル ホスピタル コーポレイション | System, apparatus and method for extending imaging depth range of optical coherence tomography through optical subsampling |
WO2010085775A2 (en) | 2009-01-26 | 2010-07-29 | The General Hospital Corporation | System, method and computer-accessible medium for providing wide-field superresolution microscopy |
CN102308444B (en) | 2009-02-04 | 2014-06-18 | 通用医疗公司 | Apparatus and method for utilization of a high-speed optical wavelength tuning source |
US8254023B2 (en) * | 2009-02-23 | 2012-08-28 | Visiongate, Inc. | Optical tomography system with high-speed scanner |
US9351642B2 (en) | 2009-03-12 | 2016-05-31 | The General Hospital Corporation | Non-contact optical system, computer-accessible medium and method for measurement at least one mechanical property of tissue using coherent speckle technique(s) |
US8155420B2 (en) * | 2009-05-21 | 2012-04-10 | Visiongate, Inc | System and method for detecting poor quality in 3D reconstructions |
BR112012001042A2 (en) | 2009-07-14 | 2016-11-22 | Gen Hospital Corp | fluid flow measurement equipment and method within anatomical structure. |
DE102009043523A1 (en) * | 2009-09-30 | 2011-04-07 | Siemens Aktiengesellschaft | endoscope |
ES2831223T3 (en) | 2010-03-05 | 2021-06-07 | Massachusetts Gen Hospital | Apparatus for providing electromagnetic radiation to a sample |
US9069130B2 (en) | 2010-05-03 | 2015-06-30 | The General Hospital Corporation | Apparatus, method and system for generating optical radiation from biological gain media |
US9557154B2 (en) | 2010-05-25 | 2017-01-31 | The General Hospital Corporation | Systems, devices, methods, apparatus and computer-accessible media for providing optical imaging of structures and compositions |
US9795301B2 (en) | 2010-05-25 | 2017-10-24 | The General Hospital Corporation | Apparatus, systems, methods and computer-accessible medium for spectral analysis of optical coherence tomography images |
EP2575591A4 (en) | 2010-06-03 | 2017-09-13 | The General Hospital Corporation | Apparatus and method for devices for imaging structures in or at one or more luminal organs |
CN101869466B (en) * | 2010-07-13 | 2012-07-18 | 苏州微清医疗器械有限公司 | Confocal scanning and optical coherence tomograph based on self-adaptive optical technology |
US9510758B2 (en) | 2010-10-27 | 2016-12-06 | The General Hospital Corporation | Apparatus, systems and methods for measuring blood pressure within at least one vessel |
US11141063B2 (en) | 2010-12-23 | 2021-10-12 | Philips Image Guided Therapy Corporation | Integrated system architectures and methods of use |
US11040140B2 (en) | 2010-12-31 | 2021-06-22 | Philips Image Guided Therapy Corporation | Deep vein thrombosis therapeutic methods |
CN102692702A (en) * | 2011-03-23 | 2012-09-26 | 中国科学院生物物理研究所 | Confocal microscope using laser interference fields |
JP5180341B2 (en) * | 2011-04-19 | 2013-04-10 | 日本電信電話株式会社 | Optical parts |
WO2012149175A1 (en) | 2011-04-29 | 2012-11-01 | The General Hospital Corporation | Means for determining depth-resolved physical and/or optical properties of scattering media |
WO2013013049A1 (en) | 2011-07-19 | 2013-01-24 | The General Hospital Corporation | Systems, methods, apparatus and computer-accessible-medium for providing polarization-mode dispersion compensation in optical coherence tomography |
US10241028B2 (en) | 2011-08-25 | 2019-03-26 | The General Hospital Corporation | Methods, systems, arrangements and computer-accessible medium for providing micro-optical coherence tomography procedures |
WO2013033489A1 (en) | 2011-08-31 | 2013-03-07 | Volcano Corporation | Optical rotary joint and methods of use |
EP2769491A4 (en) | 2011-10-18 | 2015-07-22 | Gen Hospital Corp | Apparatus and methods for producing and/or providing recirculating optical delay(s) |
JP2013200438A (en) * | 2012-03-26 | 2013-10-03 | Sinto S-Precision Ltd | Microscope |
WO2013148306A1 (en) | 2012-03-30 | 2013-10-03 | The General Hospital Corporation | Imaging system, method and distal attachment for multidirectional field of view endoscopy |
WO2013177154A1 (en) | 2012-05-21 | 2013-11-28 | The General Hospital Corporation | Apparatus, device and method for capsule microscopy |
JP6227652B2 (en) | 2012-08-22 | 2017-11-08 | ザ ジェネラル ホスピタル コーポレイション | System, method, and computer-accessible medium for fabricating a miniature endoscope using soft lithography |
US9286673B2 (en) | 2012-10-05 | 2016-03-15 | Volcano Corporation | Systems for correcting distortions in a medical image and methods of use thereof |
US11272845B2 (en) | 2012-10-05 | 2022-03-15 | Philips Image Guided Therapy Corporation | System and method for instant and automatic border detection |
US10070827B2 (en) | 2012-10-05 | 2018-09-11 | Volcano Corporation | Automatic image playback |
US10568586B2 (en) | 2012-10-05 | 2020-02-25 | Volcano Corporation | Systems for indicating parameters in an imaging data set and methods of use |
US9858668B2 (en) | 2012-10-05 | 2018-01-02 | Volcano Corporation | Guidewire artifact removal in images |
US9307926B2 (en) | 2012-10-05 | 2016-04-12 | Volcano Corporation | Automatic stent detection |
US9324141B2 (en) | 2012-10-05 | 2016-04-26 | Volcano Corporation | Removal of A-scan streaking artifact |
US9367965B2 (en) | 2012-10-05 | 2016-06-14 | Volcano Corporation | Systems and methods for generating images of tissue |
JP2015532536A (en) | 2012-10-05 | 2015-11-09 | デイビッド ウェルフォード, | System and method for amplifying light |
US9292918B2 (en) | 2012-10-05 | 2016-03-22 | Volcano Corporation | Methods and systems for transforming luminal images |
US9840734B2 (en) | 2012-10-22 | 2017-12-12 | Raindance Technologies, Inc. | Methods for analyzing DNA |
GB2508368B (en) * | 2012-11-29 | 2018-08-08 | Lein Applied Diagnostics Ltd | Optical measurement apparatus and method of manufacturing the same |
EP2931132B1 (en) | 2012-12-13 | 2023-07-05 | Philips Image Guided Therapy Corporation | System for targeted cannulation |
US10942022B2 (en) | 2012-12-20 | 2021-03-09 | Philips Image Guided Therapy Corporation | Manual calibration of imaging system |
US11406498B2 (en) | 2012-12-20 | 2022-08-09 | Philips Image Guided Therapy Corporation | Implant delivery system and implants |
JP2016506276A (en) | 2012-12-20 | 2016-03-03 | ジェレミー スティガール, | Locate the intravascular image |
US9709379B2 (en) | 2012-12-20 | 2017-07-18 | Volcano Corporation | Optical coherence tomography system that is reconfigurable between different imaging modes |
WO2014099899A1 (en) | 2012-12-20 | 2014-06-26 | Jeremy Stigall | Smooth transition catheters |
US10939826B2 (en) | 2012-12-20 | 2021-03-09 | Philips Image Guided Therapy Corporation | Aspirating and removing biological material |
US9118413B2 (en) | 2012-12-20 | 2015-08-25 | Nokia Technologies Oy | Apparatus and a method |
WO2014099672A1 (en) | 2012-12-21 | 2014-06-26 | Andrew Hancock | System and method for multipath processing of image signals |
US10166003B2 (en) | 2012-12-21 | 2019-01-01 | Volcano Corporation | Ultrasound imaging with variable line density |
US9486143B2 (en) | 2012-12-21 | 2016-11-08 | Volcano Corporation | Intravascular forward imaging device |
CA2895993A1 (en) | 2012-12-21 | 2014-06-26 | Jason Spencer | System and method for graphical processing of medical data |
US9612105B2 (en) | 2012-12-21 | 2017-04-04 | Volcano Corporation | Polarization sensitive optical coherence tomography system |
US10191220B2 (en) | 2012-12-21 | 2019-01-29 | Volcano Corporation | Power-efficient optical circuit |
US10058284B2 (en) | 2012-12-21 | 2018-08-28 | Volcano Corporation | Simultaneous imaging, monitoring, and therapy |
US10993694B2 (en) | 2012-12-21 | 2021-05-04 | Philips Image Guided Therapy Corporation | Rotational ultrasound imaging catheter with extended catheter body telescope |
US10413317B2 (en) | 2012-12-21 | 2019-09-17 | Volcano Corporation | System and method for catheter steering and operation |
US9383263B2 (en) | 2012-12-21 | 2016-07-05 | Volcano Corporation | Systems and methods for narrowing a wavelength emission of light |
WO2014120791A1 (en) | 2013-01-29 | 2014-08-07 | The General Hospital Corporation | Apparatus, systems and methods for providing information regarding the aortic valve |
US11179028B2 (en) | 2013-02-01 | 2021-11-23 | The General Hospital Corporation | Objective lens arrangement for confocal endomicroscopy |
JP6243453B2 (en) | 2013-03-07 | 2017-12-06 | ボルケーノ コーポレイション | Multimodal segmentation in intravascular images |
US10226597B2 (en) | 2013-03-07 | 2019-03-12 | Volcano Corporation | Guidewire with centering mechanism |
CN105228518B (en) | 2013-03-12 | 2018-10-09 | 火山公司 | System and method for diagnosing coronal microvascular diseases |
US20140276923A1 (en) | 2013-03-12 | 2014-09-18 | Volcano Corporation | Vibrating catheter and methods of use |
US9301687B2 (en) | 2013-03-13 | 2016-04-05 | Volcano Corporation | System and method for OCT depth calibration |
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US10219887B2 (en) | 2013-03-14 | 2019-03-05 | Volcano Corporation | Filters with echogenic characteristics |
US10292677B2 (en) | 2013-03-14 | 2019-05-21 | Volcano Corporation | Endoluminal filter having enhanced echogenic properties |
JP6378311B2 (en) | 2013-03-15 | 2018-08-22 | ザ ジェネラル ホスピタル コーポレイション | Methods and systems for characterizing objects |
WO2014186353A1 (en) | 2013-05-13 | 2014-11-20 | The General Hospital Corporation | Detecting self-interefering fluorescence phase and amplitude |
EP3021735A4 (en) | 2013-07-19 | 2017-04-19 | The General Hospital Corporation | Determining eye motion by imaging retina. with feedback |
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WO2015089308A1 (en) * | 2013-12-11 | 2015-06-18 | The General Hospital Corporation | Apparatus and method for high-speed full field optical coherence microscopy |
US9733460B2 (en) | 2014-01-08 | 2017-08-15 | The General Hospital Corporation | Method and apparatus for microscopic imaging |
WO2015116986A2 (en) | 2014-01-31 | 2015-08-06 | The General Hospital Corporation | System and method for facilitating manual and/or automatic volumetric imaging with real-time tension or force feedback using a tethered imaging device |
JP6513697B2 (en) * | 2014-03-13 | 2019-05-15 | ナショナル ユニバーシティ オブ シンガポール | Optical interference device |
WO2015153982A1 (en) | 2014-04-04 | 2015-10-08 | The General Hospital Corporation | Apparatus and method for controlling propagation and/or transmission of electromagnetic radiation in flexible waveguide(s) |
WO2016015052A1 (en) | 2014-07-25 | 2016-01-28 | The General Hospital Corporation | Apparatus, devices and methods for in vivo imaging and diagnosis |
US9958327B2 (en) | 2014-10-01 | 2018-05-01 | Nanometrics Incorporated | Deconvolution to reduce the effective spot size of a spectroscopic optical metrology device |
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GB2552195A (en) * | 2016-07-13 | 2018-01-17 | Univ Oxford Innovation Ltd | Interferometric scattering microscopy |
DE102016122528A1 (en) | 2016-11-22 | 2018-05-24 | Carl Zeiss Microscopy Gmbh | Method for controlling or regulating a microscope illumination |
DE102016122529A1 (en) * | 2016-11-22 | 2018-05-24 | Carl Zeiss Microscopy Gmbh | Microscope for imaging an object |
US10520436B2 (en) * | 2016-11-29 | 2019-12-31 | Caduceus Biotechnology Inc. | Dynamic focusing confocal optical scanning system |
WO2018169486A1 (en) * | 2017-03-15 | 2018-09-20 | Nanyang Technological University | Optical imaging device and method for imaging |
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EP3839417B1 (en) * | 2019-12-18 | 2023-08-09 | Paris Sciences et Lettres | A full-field optical coherence tomography imaging method |
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Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5412473A (en) * | 1993-07-16 | 1995-05-02 | Therma-Wave, Inc. | Multiple angle spectroscopic analyzer utilizing interferometric and ellipsometric devices |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4304464A (en) * | 1977-08-19 | 1981-12-08 | The University Of Arizona Foundation | Background compensating interferometer |
US4213706A (en) * | 1977-08-19 | 1980-07-22 | The University Of Arizona Foundation | Background compensating interferometer |
US4340306A (en) * | 1980-02-04 | 1982-07-20 | Balasubramanian N | Optical system for surface topography measurement |
US4818110A (en) * | 1986-05-06 | 1989-04-04 | Kla Instruments Corporation | Method and apparatus of using a two beam interference microscope for inspection of integrated circuits and the like |
US5112129A (en) * | 1990-03-02 | 1992-05-12 | Kla Instruments Corporation | Method of image enhancement for the coherence probe microscope with applications to integrated circuit metrology |
GB9014263D0 (en) * | 1990-06-27 | 1990-08-15 | Dixon Arthur E | Apparatus and method for spatially- and spectrally- resolvedmeasurements |
WO1992019930A1 (en) * | 1991-04-29 | 1992-11-12 | Massachusetts Institute Of Technology | Method and apparatus for optical imaging and measurement |
US5248876A (en) * | 1992-04-21 | 1993-09-28 | International Business Machines Corporation | Tandem linear scanning confocal imaging system with focal volumes at different heights |
US5248879A (en) * | 1992-10-19 | 1993-09-28 | Ncr Corporation | Circuit for adjusting the sensitivity of a sensor using a digital counter and a low-pass filter |
US5537247A (en) * | 1994-03-15 | 1996-07-16 | Technical Instrument Company | Single aperture confocal imaging system |
DE4411017C2 (en) * | 1994-03-30 | 1995-06-08 | Alexander Dr Knuettel | Optical stationary spectroscopic imaging in strongly scattering objects through special light focusing and signal detection of light of different wavelengths |
US5760901A (en) * | 1997-01-28 | 1998-06-02 | Zetetic Institute | Method and apparatus for confocal interference microscopy with background amplitude reduction and compensation |
-
1997
- 1997-01-28 US US08/789,885 patent/US5760901A/en not_active Expired - Lifetime
-
1998
- 1998-01-22 WO PCT/US1998/001214 patent/WO1998035204A1/en not_active Application Discontinuation
- 1998-01-22 EP EP98905982A patent/EP1012535A1/en not_active Withdrawn
- 1998-01-22 JP JP53470998A patent/JP4229472B2/en not_active Expired - Fee Related
- 1998-01-22 CN CNB988029790A patent/CN1146717C/en not_active Expired - Fee Related
- 1998-06-02 US US09/089,105 patent/US6091496A/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5412473A (en) * | 1993-07-16 | 1995-05-02 | Therma-Wave, Inc. | Multiple angle spectroscopic analyzer utilizing interferometric and ellipsometric devices |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003527577A (en) * | 1999-11-19 | 2003-09-16 | ザイゴ コーポレーション | System and method for quantifying nonlinearity in an interferometric measurement system |
JP4717308B2 (en) * | 1999-11-19 | 2011-07-06 | ザイゴ コーポレーション | System and method for quantifying non-linearities in an interferometric measurement system |
EP3002547B1 (en) * | 2003-06-06 | 2019-04-03 | The General Hospital Corporation | Process and apparatus for a wavelength tuning source |
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US6091496A (en) | 2000-07-18 |
US5760901A (en) | 1998-06-02 |
JP2001513191A (en) | 2001-08-28 |
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CN1249810A (en) | 2000-04-05 |
EP1012535A1 (en) | 2000-06-28 |
CN1146717C (en) | 2004-04-21 |
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