|Publication number||USRE37585 E1|
|Application number||US 09/366,685|
|Publication date||Mar 19, 2002|
|Filing date||Aug 4, 1999|
|Priority date||Apr 8, 1994|
|Also published as||CA2186451A1, CA2186451C, DE69500997D1, DE69500997T2, EP0754103A1, EP0754103B1, US5656186, WO1995027587A1|
|Publication number||09366685, 366685, US RE37585 E1, US RE37585E1, US-E1-RE37585, USRE37585 E1, USRE37585E1|
|Inventors||Gérard Mourou, Detao Du, Subrata K. Dutta, Victor Elner, Ron Kurtz, Paul R. Lichter, Xinbing Liu, Peter P. Pronko, Jeffrey A. Squier|
|Original Assignee||The Regents Of The University Of Michigan|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (48), Non-Patent Citations (29), Referenced by (231), Classifications (31), Legal Events (12)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention was made with government support provided by the Office of Naval Research and the National Science Foundation under the terms of No. STC PHY 8920108. The government has certain rights in the invention.
Notice: More than one reissue application has been filed for the reissue of U.S. Pat. No. 5,656,186. The reissue applications are application numbers 09/366,685 (the present application), which has divisional applications 09/775,069 and 09/775,106.
This invention relates generally to methods utilizing lasers for modifying internal and external surfaces of material such as by ablation or changing properties in structure of materials. This invention may be used for a variety of materials.
Laser induced breakdown of a material causes chemical and physical changes, chemical and physical breakdown, disintegration, ablation, and vaporization. Lasers provide good control for procedures which require precision such as inscribing a micro pattern. Pulsed rather than continuous beams are more effective for many procedures, including medical procedures. A pulsed laser beam comprises bursts or pulses of light which are of very short duration, for example, on the order of 10 nanoseconds in duration or less. Typically, these pulses are separated by periods of quiescence. The peak power of each pulse is relatively high often on the order of gigawatts and capable of intensity on the order of 1013 w/cm2. Although the laser beam is focused onto an area having a selected diameter, the effect of the beam extends beyond the focused area or spot to adversely affect peripheral areas adjacent to the spot. Sometimes the peripheral area affected is several times greater than the spot itself. This presents a problem, particularly where tissue is affected in a medical procedure. In the field of laser machining, current lasers using nanosecond pulses cannot produce features with a high degree of precision and control, particularly when nonabsorptive wavelengths are used.
It is a general object to provide a method to localize laser induced breakdown. Another object is to provide a method to induce breakdown in a preselected pattern in a material or on a material.
In one aspect the invention provides a method for laser induced breakdown of a material with a pulsed laser beam where the material is characterized by a relationship of fluence breakdown threshold (Fth) versus laser beam pulse width (T) that exhibits an abrupt, rapid, and distinct change or at least a clearly detectable and distinct change in slope at a predetermined laser pulse width value. The method comprises generating a beam of laser pulses in which each pulse has a pulse width equal to or less than the predetermined laser pulse width value. The beam is focused to a point at or beneath the surface of a material where laser induced breakdown is desired.
In one aspect, the invention may be understood by further defining the predetermined laser pulse width as follows: the relationship between fluence breakdown threshold and laser pulse defines a curve having a first portion spanning a range of relatively long (high) pulse width where fluence breakdown threshold (Fth) varies with the square root of pulse width (T1/2). The curve has a second portion spanning a range of short (low) pulse width relative to the first portion. The proportionality between fluence breakdown threshold and pulse width differ in the first and second portions of the curve and the predetermined pulse width is that point along the curve between its first and second portions. In other words, the predetermined pulse width is the point where the Fth versus τp relationship no longer applies, and, of course, it does not apply for pulse widths shorter than the predetermined pulse width.
The scaling of fluence breakdown threshold (Fth) as a function of pulse width (T) is expressed as Fth proportional to the square root of (T1/2) is demonstrated in the pulse width regime to the nanosecond range. The invention provides methods for operating in pulse widths to the picosecond and femtosecond regime where we have found that the breakdown threshold (Fth) does not vary with the square root of pulse width (T1/2).
Pulse width duration from nanosecond down to the femtosecond range is accomplished by generating a short optical pulse having a predetermined duration from an optical oscillator. Next the short optical pulse is stretched in time by a factor of between about 500 and 10,000 to produce a timed stretched optical pulse to be amplified. Then, the time stretched optical pulse is amplified in a solid state amplifying media. This includes combining the time stretched optical pulse with an optical pulse generated by a second laser used to pump the solid state amplifying media. The amplified pulse is then recompressed back to its original pulse duration.
In one embodiment, a laser oscillator generates a very short pulse on the order of 10 to 100 femtoseconds at a relatively low energy, on the order of 0.001 to 10 nanojoules. Then, it is stretched to approximately 100 picoseconds to 1 nanosecond and 0.001 to 10 nanojoules. Then, it is amplified to typically on the order of 0.001 to 1.000 millijoules and 100 picoseconds to 1 nanosecond and then recompressed. In its final state it is 10 to 200 femtoseconds and 0.001 to 1.000 millijoules. Although the system for generating the pulse may vary, it is preferred that the laser medium be sapphire which includes a titanium impurity responsible for the lasing action.
In one aspect, the method of the invention provides a laser beam which defines a spot that has a lateral gaussian profile characterized in that fluence at or near the center of the beam spot is greater than the threshold fluence whereby the laser induced breakdown is ablation of an area within the spot. The maximum intensity is at the very center of the beam waist. The beam waist is the point in the beam where wave-front becomes a perfect plane; that is, its radius of curvature is infinite. This center is at radius R=0 in the x-y axis and along the Z axis, Z=0. This makes it possible to damage material in a very small volume Z=0, R=0. Thus it is possible to make features smaller than spot size in the x-y focal plane and smaller than the Rayleigh range (depth of focus) in the Z axis. It is preferred that the pulse width duration be in the femtosecond range although pulse duration of higher value may be used so long as the value is less than the pulse width defined by an abrupt or discernable change in slope of fluence breakdown threshold versus laser beam pulse width.
In another aspect, a diaphragm, disk, or mask is placed in the path of the beam to block at least a portion of the beam to cause the beam to assume a desired geometric configuration. In still further aspects, desired beam configurations are achieved by varying beam spot size or through Fourier Transform (FT) pulse shaping to cause a special frequency distribution to provide a geometric shape.
It is preferred that the beam have an energy in the range of 10 nJ (nanojoules) to 1 millijoule and that the beam have a fluence in the range of 0.1 J/cm2 to 100 J/cm2 (joules per centimeter square). It is preferred that the wavelength be in a range of 200 nm (nanometer) to 1 μm (micron).
Advantageously, the invention provides a new method for determining the optimum pulse width duration regime for a specific material and a procedure for using such regime to produce a precisely configured cut or void in or on a material. For a given material the regime is reproducible by the method of the invention. Advantageously, very high intensity results from the method with a modest amount of energy and the spot size can be very small. Damage to adjoining area is minimized which is particularly important to human and animal tissue.
These and other object features and advantages of the invention will be become apparent from the following description of the preferred embodiments, claims, and accompanying drawings.
FIG. 1 is a schematic representation of a laser induced breakdown experimental system which includes a chirped pulse amplification laser system and means for detecting scattered and transmitted energy. If the sample is transparent, then transmitted energy can also be measured.
FIG. 2 is a plot of scattered energy versus incident fluence obtained for an opaque (gold) sample using the system in FIG. 1 operated for 150 femtoseconds (fs) pulse duration.
FIG. 3 is a plot of calculated and experimental values of threshold fluence versus pulse width for gold, with experimental values obtained for the gold sample using the system of FIG. 1 operated at 800 nm wavelength. The arrow shows the point on the plot where the Fth proportional to T1/2 no longer applies, as this relationship only holds for pulse widths down to a certain level as shown by the solid line.
FIG. 4 is a graphical representation of sub-spot size ablation/machining in gold based on arbitrary units and showing Fth the threshold fluence needed to initiate material removal; Rs the spot size of the incident beam and Ra the radius of the ablated hole in the x-y plane.
FIG. 5 is a schematic illustration of a beam intensity profile showing that for laser micro-machining with ultrafast pulse according to the invention, only the peak of the beam intensity profile exceeds the threshold intensity for ablation/machining.
FIG. 6A and B are schematic illustrations of a beam showing the placement of a disk-shaped mask in the beam path.
FIG. 7 is a plot of scattered plasma emission and transmitted laser pulse as a function of incident laser pulse energy for a transparent glass sample, SiO2.
FIG. 8 is a plot of fluence threshold (Fth) versus pulse width (T) for the transparent glass sample of FIG. 7 showing that Fth varying with T1/2 only holds for pulse widths down to a certain level as shown by the solid line. Previous work of others is shown in the long pulse width regime (Squares, Smith Optical Eng 17, 1978 and Triangles. Stokowski, NBS Spec Bul 541, 1978).
FIG. 9 is a plot of fluence threshold versus pulse width for corneal tissue, again showing that the proportionality between Fth and pulse width follows the T1/2 relationship only for pulse widths which are relatively long.
FIGS. 10 and 11 are plots of plasma emission versus laser fluence showing that at 170 (FIG. 10) pulse width the Fth is very clearly defined compared to 7 nm (FIG. 11) pulse width where it is very unclear.
FIG. 12 is a plot of impact ionization rate per unit distance determined by experiment and theoretical calculation.
FIGS. 13A and B are schematic illustrations of beam profile along the longitudinal Z axis and sharing precise control of damage—dimension along the Z axis.
Referring to FIG. 1 there is shown an apparatus for performing tests to determine the laser induced breakdown threshold as a function of laser pulse width in the nanosecond to femtosecond range using a chirped-pulse amplification (CPA) laser system. The basic configuration of such a CPA system is described in U.S. Pat. No. 5,235,606 which is assigned to the assignee of the present invention and which has inventors in common with this present application. U.S. Pat. No. 5,235,606 is incorporated herein by reference in its entirety.
Chirped-pulse amplification systems have been described by Jeffrey Squier and Gerard Mourou, two of the joint inventors in the present application, in a publication entitled Laser Focus World published by Pennwell in June of 1992. It is described that CPA systems can be roughly divided into four categories. The first includes the high energy low repetition systems such as ND glass lasers with outputs of several joules but they may fire less than 1 shot per minute. A second category are lasers that have an output of approximately 1 joule and repetition rates from 1 to 20 hertz. The third group consists of millijoule level lasers that operate at rates ranging from 1 to 10 kilohertz. A fourth group of lasers operates at 250 to 350 kilohertz and produces a 1 to 2 microjoules per pulse. In U.S. Pat. No. 5,235,606 several solid state amplifying materials are identified and the invention of U.S. Pat. No. 5,235,606 is illustrated using the Alexandrite. The examples below use Ti:Sapphire and generally follow the basic process of U.S. Pat. No. 5,235,606 with some variations as described below.
The illustrative examples described below generally pertain to pulse energies less than a microjoule and often in the nanojoule range with pulse duration in the range of hundreds of picoseconds or less and the frequency on the order of 1 kilohertz. But these examples are merely illustrative and the invention is not limited thereby.
In a basic scheme for CPA, first a short pulse is generated. Ideally the pulse from the oscillator is sufficiently short so that further pulse compression is not necessary. After the pulse is produced it is stretched by a grating pair arranged to provide positive group velocity dispersion. The amount the pulse is stretched depends on the amount of amplification. Below a millijoule, tens of picoseconds are usually sufficient. A first stage of amplification typically takes place in either a regenerative or a multipass amplifier. In one configuration this consists of an optical resonator that contains the gain media, a Pockels cell, and a thin film polarizer. After the regenerative amplification stage the pulse can either be recompressed or further amplified. The compressor consists of a grating or grating pair arranged to provide negative group velocity dispersion. Gratings are used in the compressor to correspond to those in the stretching stage. More particulars of a typical system are described in U.S. Pat. No. 5,235,606, previously incorporated herein by reference.
An important aspect of the invention is the development of a characteristic curve of fluence breakdown threshold Fth as a function of laser pulse width specific to a material. Then identify on such curve, the point at which there is an abrupt, or distinct and rapid change or at least a discernable change in slope characteristic of the material. In general it is more desirable to operate past this point because of the more precise control of the laser induced breakdown (LIB) or ablation threshold.
FIG. 1 shows an experimental setup for determining threshold fluence by determining scattered energy versus incident fluence and by determining threshold fluence versus pulse width. The system includes means for generating a pulsed laser beam as described earlier, and means, typically a lens, for collecting emission from the target to a photomultiplier tube. Change of transmission through a transparent sample is measured with an energy meter.
FIG. 2 shows a plot of data obtained from an absorbing medium which is gold using 150 fs pulse and FIG. 3 shows threshold fluence versus pulse width. The arrow in FIG. 3 identifies the point at which the relationship between the threshold fluence and pulse width varies dramatically.
In experimental conditions with wavelength of 800 nm and 200 fs pulses on gold (FIG. 3), the absorption depth is 275 A with a diffusion length of 50 A. In the case of nanosecond pulses the diffusion length, which is on the order of 10 μm (micron) in diameter, is much longer than the absorption depth, resulting in thermal diffusion being the limiting factor in feature size resolution. Empirical evidence for the existence of these two regimes is as exhibited in FIG. 3. Here both experimental and theoretical ablation thresholds are plotted as a function of pulse width. An arrow at approximately 7 picoseconds pulse width (designated herein as T or τp) delineates the point (or region closely bounding that point) at which the thermal diffusion length (Lth) is equal to the absorption depth (1/a). It is clear that for a smaller size spot a shorter (smaller) pulse is necessary. For spot size on the order of 1000 Å or less, pulse width on the order of 100 femtoseconds or less will be needed. It is clear from the figure that this is the point at which the ablation threshold transitions from a slowly varying or nearly constant value as a function of pulse width to one that is dramatically dependent on pulse time. This result is surprising. It has been demonstrated that the electron thermalization time for laser deposited energy in gold is on the order of, or less than, 500 fs and the electron-lattice interaction time is 1 ps. The consequences of this four ultrafast laser pulses is that the energy is contained within the beam spot. In fact for energies at or near the threshold for ablation, the spatial profile of the laser beam will determine the size and shape of the region being ablated (FIGS. 4 and 5).
Additional experiments were performed to measure the amount of recombination light produced as a function of the fluence impinging on a gold film. The technique involved is based upon the experimental setup previously described. A basic assumption is that the intensity of the light is proportional to the amount of material ablated. In FIG. 4, the material removed is plotted as a function of fluence. A well defined threshold fluence is observed at which material removal is initiated. By having only a small fraction of the gaussian beam where the fluence is greater than the threshold, the ablated region can be restricted to this small area. In FIG. 4, Ra is the radial position on the beam where the fluence is at threshold. Ablation, then, occurs only within a radius Ra. It is evident that by properly choosing the incident fluence, the ablated spot or hole can in principle be smaller than the spot size, Rs. This concept is shown schematically in FIG. 5. Although the data for a 150 fs pulse is shown in FIG. 4, this threshold behavior is exhibited in a wide range of pulse widths. However, sub spot size ablation is not possible in the longer pulse regimes, due to the dominance of thermal diffusion as will be described below.
Additional experiments on opaque materials used a 800 nm Ti:Sapphire oscillator whose pulses were stretched by a grating pair, amplified in a regenerative amplifier operating at 1 kHz, and finally recompressed by another grating pair. Pulse widths from 7 ns to 100 fs were obtained. The beam was focused with a 10× objective, implying a theoretical spot size of 3.0 μm in diameter. A SEM photo-micrograph of ablated holes obtained in a silver film on glass, using a pulse width of 200 fs and a pulse energy of 30 nJ (fluence of 0.4 J/cm2) produced two holes of diameter approximately 0.3 μm in diameter. Similar results have been obtained in aluminum.
These results suggest that by, producing a smaller spot size which is a function of numerical aperture and wavelength, even smaller holes can be machined. We have demonstrated the ability to generate the fourth harmonic (200 nm) using a nonlinear crystal. Thus by using a stronger objective lens along with the 200 nm light, holes with diameters of 200 angstroms could in principle be formed.
These examples show that by using femtosecond pulses the spatial resolution of the ablation/machining process can be considerably less than the wavelength of the laser radiation used to produce it. The ablated holes have an area or diameter less than the area or diameter of the spot size. In the special case of diffraction limited spot size, the ablated hole has a size (diameter) less than the fundamental wavelength size. We have produced laser ablated holes with diameters less than the spot diameter and with diameters 10% or less of the laser beam spot size. For ultrafast pulses in metals the thermal diffusion length, lth=(Dt)1/2 (where D is the thermal diffusivity and t the pulse time), is significantly smaller than the absorption depth (1/a), where a is the absorption coefficient for the radiation.
Those skilled in the art will understand that the basic method of the invention may be utilized in alternative embodiments depending on the desired configurations of the induced breakdown. Examples include, but are not limited to using a mask in the beam path, varying spot size, adjusting focus position by moving the lens, adjusting laser cavity design, Fourier Transform (FT) shaping, using a laser operating mode other than TEMoo, and adjusting the Rayleigh range, the depth of focus or beam waist.
The use of a mask is illustrated in FIG. 6A and B. The basic method consists of placing a mask in the beam path or on the target itself. If it is desired to block a portion of the beam, the mask should be made of an opaque material and be suspended in the beam path (FIG. 6) alternatively, the mask may be placed on the target and be absorptive so as to contour the target to the shape of the mask (FIG. 6B).
The varying spot size is accomplished by varying the laster f/#, varying the focal length of the lens or input beam size to the lens as by adjustable diaphragm.
Operation in other than the TEMoo mode means that higher order transverse modes could be used. This affects the beam and material as follows: the beam need not be circular or gaussian in intensity. The material will be ablated corresponding to the beam shape.
The Rayleigh range (Z axis) may be adjusted by varying the beam diameter, where the focal plane is in the x-y axis.
A series of tests were performed on an SiO2 (glass) sample to determine the laser induced breakdown (LIB) threshold as a function of laser pulse width between 150 fs-7 ns, using a CPA laser system. The short pulse laser used was a 10 Hz Ti:Sapphire oscillator amplifier system based on the CPA technique. The laser pulse was focused by an f=25 cm lens inside the SiO2 sample. The Rayleigh length of the focused beam is ˜2 mm. The focused spot size was measured in-situ by a microscope objective lens. The measured spot size FWHM (full width at half max) was 26 μm in diameter in a gaussian mode. The fused silica samples were made from Corning 7940, with a thickness of 0.15 mm. They were optically polished on both sides with a scratch/dig of 20-10. Each sample was cleaned by methanol before the experiment. Thin samples were used in order to avoid the complications of self-focusing of the laser pulses in the bulk. The SiO2 sample was mounted on a computer controlled motorized X-Y translation stage. Each location on the sample was illuminated by the laser only once.
Two diagnostics were used to determine the breakdown threshold Fth. First, the plasma emission from the focal region was collected by a lens to a photomultiplier tube with appropriate filters. Second, the change of transmission through the sample was measured with an energy meter. (See FIG. 1) Visual inspection was performed to confirm the breakdown at a nanosecond pulse duration. FIG. 7 shows typical plasma emission and transmitted light signal versus incident laser energy plots, at a laser pulse width of τp=300 fs. It is worth noting that the transmission changed slowly at around Fth. This can be explained by the temporal and spatial behavior of the breakdown with ultrashort pulses. Due to the spatial variation of the intensity, the breakdown will reach threshold at the center of the focus, and because of the short pulse duration, the generated plasma will stay localized. The decrease in transmitted light is due to the reflection, scattering, and absorption by the plasma. By assuming a gaussian profile in both time and space for the laser intensity, and further assuming that the avalanche takes the entire pulse duration to reach threshold, one can show that the transmitted laser energy Ut as a function of the input energy U is given by
where k is the linear transmission coefficient. The solid curve in FIG. 7 is plotted using Eq. (1) with Uth as a fitting parameter. In contrast, breakdown caused by nanosecond laser pulses cuts off the transmitted beam near the peak of the pulses, indicating a different temporal and spatial behavior.
FIG. 8 shows the fluence breakdown threshold Fth as a function of laser pulse width. From 7 ns to about 10 ps, the breakdown threshold follows the scaling in the relatively long pulse width regime (triangles and squares) are also shown as a comparison—it can be seen that the present data is consistent with earlier work only in the higher pulse width portion of the curve. When the pulse width becomes shorter than a few picoseconds, the threshold starts to increase. As noted earlier with respect to opaque material (metal), this increased precision at shorter pulse widths is surprising. A large increase in damage threshold accuracy is observed, consistent with the multiphoton avalanche breakdown theory. (See FIGS. 8 and 9). It is possible to make features smaller than spot size in the x-y focal plane and smaller than the Rayleigh range (depth of focus) in the longitudinal direction or Z axis. These elements are essential to making features smaller than spot size or Rayleigh range.
A series of experiments was performed to determine the breakdown threshold of cornea as a function of laser pulse width between 150 fs-7 ns, using a CPA laser system. As noted earlier, in this CPA laser system, laser pulse width can be varied while all other experimental parameters (spot size, wavelength, energy, etc.) remain unchanged. The laser was focused to a spot size (FWHM) of 26 μm in diameter. The plasma emission was recorded as a function of pulse energy in order to determine the tissue damage threshold. Histologic damage was also assessed.
Breakdown thresholds calculated from plasma emission data revealed deviations from the scaling law. Fth α T1/2, as in the case of metals and glass. As shown in FIG. 9, the scaling law of the fluence threshold is true to about 10 ps, and fail when the pulse shortens to less than a few picoseconds. As shown in FIGS. 10 and 11, the ablation or LIB threshold varies dramatically at high (long) pulse width. It is very precise at short pulse width. These results were obtained at 770 nm wavelength. The standard deviation of breakdown threshold measurements decreased markedly with shorter pulses. Analysis also revealed less adjacent histological damage with pulses less than 10 ps.
The breakdown threshold for ultrashort pulses (<10 ps) is less than longer pulses and has smaller standard deviations. Reduced adjacent histological damage to tissue results from the ultrashort laser pulses.
In summary, it has been demonstrated that sub-wavelength holes can be machined into metal surfaces using femtosecond laser pulses. The effect is physically understood in terms of the thermal diffusion length, over the time period of the pulse deposition, being less than the absorption depth of the incident radiation. The interpretation is further based on the hole diameter being determined by the lateral gaussian distribution of the pulse in relation to the threshold for vaporization and ablation.
Laser induced optical breakdown dielectrics consists of three general steps: free electron generation and multiplication, plasma heating and material deformation or breakdown. Avalanche ionization and multiphoton ionization are the two processes responsible for the breakdown. The laser induced breakdown threshold in dielectric material depends on the pulse width of the laser pulses. An empirical scaling law of the fluence breakdown threshold as a function of the pulse width is given by Fth α τp, or alternatively, the intensity breakdown threshold, Ith=Fth/τp. Although this scaling law applies in the pulse width regime from nanosecond to tens of picoseconds, the invention takes advantage of the heretofore unknown regime where breakdown threshold does not follow the scaling law when suitably short laser pulses are used, such as shorter than 7 picoseconds for gold and 10 picoseconds for SiO2.
While not wishing to be held to any particular theory, it is thought that the ionization process of a solid dielectric illuminated by an intense laser pulse can be described by the general equation
where ne(t) is the free electron (plasma) density, η(E) is the avalanche coefficient, and E is the electric field strength. The second term on the right hand side is the photoionization contribution, and the third term is the loss due to electron diffusion, recombination, etc. When the pulse width is in the picosecond regime, the loss of the electron is negligible during the duration of the short pulse.
Photoionization contribution can be estimated by the tunneling rate. For short pulses, E˜108 V/cm, the tunneling rate is estimated to be w˜4×109 sec−1, which is small compared to that of avalanche, which is derived below. However, photoionization can provide the initial electrons needed for the avalanche processes at short pulse widths. For example, the data shows at 1 ps, the rms field threshold is about 5×107 V/cm. The field will reach a value of 3.5×107 V/cm (ms) at 0.5 ps before the peak of the pulse, and w˜100 sec−1. During a Δt˜100 fs period the electron density can reach ne˜nt[1−exp(−wΔt)]˜1011 cm−3, where nt˜1022 is the total initial valence band electron density.
Neglecting the last two terms there is the case of an electron avalanche process, with impact ionization by primary electrons driven by the laser field. The electron density is then given by ne(t)=no×exp(n(E)t), where no is the initial free electron density. These initial electrons may be generated through thermal ionization of shallow traps or photoionization. When assisted by photoionization at short pulse regime, the breakdown is more statistical. According to the condition that breakdown occurs when the electron density exceeds nth≅1018 cm−3 and an initial density of no≅1910 cm−3, the breakdown condition is then given by ητp≅18. For the experiment, it is more appropriate to use nth≅1.6×1021 cm−3, the plasma critical density, hence the threshold is reached when ητp≅30. There is some arbitrariness in the definition of plasma density relating to the breakdown threshold. However, the particular choice of plasma density does not change the dependence of threshold as function of pulse duration (the scaling law).
In the experiment, the applied electric field is on the order of a few tens of MV/cm and higher. Under such a high field, the electrons have an average energy of ˜5 eV, and the electron collision time is less than 0.4 fs for electrons with energy U≧5-6 eV. Electrons will make more than one collision during one period of the electric oscillation. Hence the electric field is essentially a dc field to those high energy electrons. The breakdown field at optical frequencies has been shown to correspond to dc breakdown field by the relationship Ermk th(w)=Edc TH(1+w2τ2)1/2, where w is the optical frequency and τ is the collision time.
In dc breakdown, the ionization rate per unit length, α, is used to describe the avalanche process, with η=α(E)vdrift, where vdrift is the drift velocity of electrons. When the electric field is as high as a few MV/cm, the drift velocity of free electrons is saturated and independent of the laser electric field, vdrift≅2×107 cm/s.
The ionization rate per unit length of an electron is just eE/Ui times the probability, P(E), that the electron has an energy ≧Ui, or α(E)=(eE/Ui)P(E). Denoting EkT,Ep, and Ei as threshold fields for electrons to overcome the decelerating effects of thermal, phonon, and ionization scattering, respectively. Then the electric field is negligible, E<EkT, so the distribution is essentially thermal, P(E) is simply exp(−Ui/kT). It has been suggested: P(E)˜exp(−const/E) for EkT<E<Ep; P(E)˜exp(−const/E2) at higher fields (E>Ep). Combining the three cases the expression that satisfies both low and high field limits:
This leads to Fth α E2τp˜1/τp, i.e., the fluence threshold will increase for ultrashort laser pulses when E>EpEi is satisfied.
FIG. 12 is a plot of α as a function of the electric field, E. From experimental data, calculated according to ητp=30 and η=avdrift. The solid curve is calculated from the above equation, using Ei=30 MV/cm, Ep=3.2 MV/cm, and EkT=0.01 MV/cm. These parameters are calculated from U=eEl, where U is the appropriate thermal, phonon, and ionization energy, and l is the correspondent energy, relation length (lkT=lp˜5 Å, the atomic spacing, and li≅30 Å). It shows the same saturation as the experimented data. The dashed line is corrected by a factor of 1.7, which results in an excellent fit with the experimental data. This factor of 1.7 is of relatively minor importance, as it can be due to a systematic correction, or because breakdown occurred on the surface first, which could have a lower threshold. The uncertainty of the saturation value of vdrift also can be a factor. The most important aspect is that the shape (slope) of the curve given by the equation provides excellent agreement with the experimental data. Thus, the mechanism of laser induced breakdown in fused silica (Example 2), using pulses as short as 150 fs and wavelength at 780 nm, is likely still dominated by the avalanche process.
Opaque and transparent materials have common characteristics in the curves of FIGS. 3, 8, and 9 each begins with Fth versus T1/2 behavior but then distinct change from that behavior is evident. From the point of deviation, each curve is not necessarily the same since the materials differ. The physical characteristics of each material differ requiring a material specific analysis. In the case of SiO2 (FIG. 8) the energy deposition mechanism is by dielectric breakdown. The optical radiation is releasing electrons by multiphoton ionization (M PI) that are tightly bound and then accelerating them to higher energies by high field of the laser. It is thought that only a small amount of relatively high energy electrons exist prior to the laser action. The electrons in turn collide with other bound electrons and release them in the avalanching process. In the case of metal, free electrons are available and instantly absorbing and redistributing energy. For any material, as the pulses get shorter laser induced breakdown (LIB) or ablation occurs only in the area where the laser intensity exceeds LIB or ablation threshold. There is essentially insufficient time for the surrounding area to react thermally. As pulses get shorter, vapor from the ablated material comes off after the deposition of the pulse, rather than during deposition, because the pulse duration is so short. In summary, by the method of the invention, laser induced breakdown of a material causes thermal-physical changes through ionization, free electron multiplication, dielectric breakdown, plasma formation, other thermal-physical changes in state, such as melting and vaporization, leading to an irreversible change in the material. It was also observed that the laser intensity also varies along the propagation axis (FIG. 13). The beam intensity as a function of R and Z expressed as:
where ZR is the Rayleigh range and is equal to
Wo is the beam size at the waist (Z=0).
We can see that the highest value of the field is at Z=R=0 at the center of the waist. If the threshold is precisely defined it is possible to damage the material precisely at the waist and have a damaged volume representing only a fraction of the waist in the R direction or in the Z direction. It is very important to control precisely the damage threshold or the laser intensity fluctuation.
For example, if the damage threshold or the laser fluctuations known within 10% that means that on the axis (R=0)
damaged volume can be produced at a distance ZR/3 where ZR again is the Rayleigh range. For a beam waist of Wo=λ then
and the d distance between hole can
as shown in FIG. 13.
The maximum intensity is exactly at the center of the beam waist (Z=0, R=0). For a sharp threshold it is possible to damage transparent, dielectric material in a small volume centered around the origin point (Z=0, R=0). The damage would be much smaller than the beam waist in the R direction. Small cavities, holes, or damage can have dimensions smaller than the Rayleigh range (ZR) in the volume of the transparent, dielectric material. In another variation, the lens can be moved to increase the size of the hole or cavity in the Z direction. In this case, the focal point is essentially moved along the Z axis to increase the longitudinal dimension of the hole or cavity. These features are important to the applications described above and to related applications such as micro machining, integrated circuit manufacture, and encoding data in data storage media.
Advantageously, the invention identifies the regime where breakdown threshold fluence does not follow the scaling law and makes use of such regime to provide greater precision of laser induced breakdown, and to induce breakdown in a preselected pattern in a material or on a material. The invention makes it possible to operate the laser where the breakdown or ablation threshold becomes essentially accurate. The accuracy can be clearly seen by the I-bars along the curves of FIGS. 8 and 9. The I-bars consistently show lesser deviation and correspondingly greater accuracy in the regime at or below the predetermined pulse width.
While this invention has been described in terms of certain embodiment thereof, it is not intended that it be limited to the above description, but rather only to the extent set forth in the following claims.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined in the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3720213 *||Feb 5, 1971||Mar 13, 1973||Coherent Radiation||Laser photocoagulator|
|US4001840 *||Oct 7, 1974||Jan 4, 1977||Precision Instrument Co.||Non-photographic, digital laser image recording|
|US4087672 *||Jul 7, 1976||May 2, 1978||United Kingdom Atomic Energy Authority||Laser removal of material from workpieces|
|US4114018 *||Sep 30, 1976||Sep 12, 1978||Lasag Ag||Method for ablating metal workpieces with laser radiation|
|US4289378 *||Oct 15, 1979||Sep 15, 1981||Ernst Remy||Apparatus for adjusting the focal point of an operating laser beam focused by an objective|
|US4464761 *||Dec 18, 1981||Aug 7, 1984||Alfano Robert R||Chromium-doped beryllium aluminum silicate laser systems|
|US4579430 *||Dec 9, 1983||Apr 1, 1986||Carl-Zeiss-Stiftung||Method and apparatus for forming an image of the ocular fundus|
|US4630274 *||Nov 20, 1984||Dec 16, 1986||Max-Planck-Geselschaft Zur Foerderung Der Wissenschaften E.V.||Method and apparatus for generating short intensive pulses of electromagnetic radiation in the wavelength range below about 100 nm|
|US4665913 *||Jun 24, 1985||May 19, 1987||Lri L.P.||Method for ophthalmological surgery|
|US4675500 *||Oct 29, 1984||Jun 23, 1987||Gretag Aktiengesellschaft||Laser processing apparatus with means for selectively varying the transverse mode distribution of the laser beam|
|US4712543 *||Jul 23, 1984||Dec 15, 1987||Baron Neville A||Process for recurving the cornea of an eye|
|US4727381 *||Jul 23, 1985||Feb 23, 1988||Josef Bille||Appartus for, and methods of, inscribing patterns on semiconductor wafers|
|US4729372 *||Jul 31, 1986||Mar 8, 1988||Lri L.P.||Apparatus for performing ophthalmic laser surgery|
|US4732473 *||Jun 7, 1985||Mar 22, 1988||Josef Bille||Apparatus for, and methods of, determining the characteristics of semi-conductor wafers|
|US4733660 *||Dec 10, 1986||Mar 29, 1988||Medical Laser Research And Development Corporation||Laser system for providing target specific energy deposition and damage|
|US4764930 *||Jan 27, 1988||Aug 16, 1988||Intelligent Surgical Lasers||Multiwavelength laser source|
|US4838679 *||Feb 28, 1985||Jun 13, 1989||Josef Bille||Apparatus for, and method of, examining eyes|
|US4839493 *||Jul 5, 1985||Jun 13, 1989||Gerd Herziger||Arrangement for machining workpieces by means of a laser beam by building up a plasma that is to be kept within limits|
|US4848340 *||Feb 10, 1988||Jul 18, 1989||Intelligent Surgical Lasers||Eyetracker and method of use|
|US4881808 *||Feb 10, 1988||Nov 21, 1989||Intelligent Surgical Lasers||Imaging system for surgical lasers|
|US4901718 *||Feb 2, 1988||Feb 20, 1990||Intelligent Surgical Lasers||3-Dimensional laser beam guidance system|
|US4907586 *||Mar 31, 1988||Mar 13, 1990||Intelligent Surgical Lasers||Method for reshaping the eye|
|US4925523 *||Jul 17, 1989||May 15, 1990||International Business Machines Corporation||Enhancement of ultraviolet laser ablation and etching organic solids|
|US4930505 *||Oct 5, 1987||Jun 5, 1990||Helmut K. Pinsch Gmbh & Co.||Method of enhancing the well-being of a living creature|
|US4942586 *||Apr 25, 1989||Jul 17, 1990||Intelligent Surgical Lasers Inc.||High power diode pumped laser|
|US4988348 *||May 26, 1989||Jan 29, 1991||Intelligent Surgical Lasers, Inc.||Method for reshaping the cornea|
|US5062702 *||Mar 16, 1990||Nov 5, 1991||Intelligent Surgical Lasers, Inc.||Device for mapping corneal topography|
|US5093548 *||Oct 17, 1990||Mar 3, 1992||Robert Bosch Gmbh||Method of forming high precision through holes in workpieces with a laser beam|
|US5098426 *||Feb 6, 1989||Mar 24, 1992||Phoenix Laser Systems, Inc.||Method and apparatus for precision laser surgery|
|US5141506 *||Mar 27, 1991||Aug 25, 1992||York Kenneth K||Systems and methods for creating substrate surfaces by photoablation|
|US5207668 *||May 31, 1991||May 4, 1993||Visx Incorporated||Method for opthalmological surgery|
|US5208437 *||May 9, 1991||May 4, 1993||Hitachi, Ltd.||Method of cutting interconnection pattern with laser and apparatus thereof|
|US5219343 *||May 15, 1991||Jun 15, 1993||Visx Incorporated||Apparatus for performing ophthalmogolical surgery|
|US5235606 *||Oct 29, 1991||Aug 10, 1993||University Of Michigan||Amplification of ultrashort pulses with nd:glass amplifiers pumped by alexandrite free running laser|
|US5246435 *||Feb 25, 1992||Sep 21, 1993||Intelligent Surgical Lasers||Method for removing cataractous material|
|US5269778 *||Sep 26, 1991||Dec 14, 1993||Rink John L||Variable pulse width laser and method of use|
|US5280491 *||Aug 2, 1991||Jan 18, 1994||Lai Shui T||Two dimensional scan amplifier laser|
|US5289407 *||Jul 22, 1991||Feb 22, 1994||Cornell Research Foundation, Inc.||Method for three dimensional optical data storage and retrieval|
|US5312396 *||Jan 22, 1991||May 17, 1994||Massachusetts Institute Of Technology||Pulsed laser system for the surgical removal of tissue|
|US5335258 *||Mar 31, 1993||Aug 2, 1994||The United States Of America As Represented By The Secretary Of The Navy||Submicrosecond, synchronizable x-ray source|
|US5348018 *||Nov 25, 1991||Sep 20, 1994||Alfano Robert R||Method for determining if tissue is malignant as opposed to non-malignant using time-resolved fluorescence spectroscopy|
|US5389786 *||Apr 15, 1993||Feb 14, 1995||President Of Nagoya University||Method of quantitative determination of defect concentration on surfaces|
|US5454902 *||Sep 24, 1992||Oct 3, 1995||Hughes Aircraft Company||Production of clean, well-ordered CdTe surfaces using laser ablation|
|US5558789 *||Mar 2, 1994||Sep 24, 1996||University Of Florida||Method of applying a laser beam creating micro-scale surface structures prior to deposition of film for increased adhesion|
|US5984916 *||Apr 20, 1993||Nov 16, 1999||Lai; Shui T.||Ophthalmic surgical laser and method|
|DE4119024A1 *||Jun 10, 1991||Dec 17, 1992||Technolas Laser Technik Gmbh||Vorrichtung zur schonenden und exakten photoablation fuer photorefraktive chirurgie|
|JPS6293095A *||Title not available|
|WO1989008529A1 *||Mar 17, 1989||Sep 21, 1989||Max-Planck-Gesellschaft Zur Förderung Der Wissensc||Process for ablation of polymer plastics using ultra-short laser pulses|
|1||A.M. Malvezzi, N. Bloembergen, and C.Y. Huang, "Time-Resolved Picosecond Optical Measurements of Laser-Excited Graphite", Physical Review Letters, vol. 57, No. 1, 146-149, Jul. 7, 1986.*|
|2||B. Frueh, J. Bille, and S. Brown, "Intrastromal Relaxing Excisions in Rabbits with a Picosecond Infrared Laser", Lasers and Light in Opthamology, vol. 4, No. 3/4, pp. 165-168, (1992).*|
|3||B. Zysset, J. Fujimoto, and T. Deutsch, "Time-Resolved Measurements of Picosecond Optical Breakdown", Applied Physics B48, 139-147 (1989).*|
|4||B. Zysset, J. Fujimoto, C. Puliafito, R. Bingruber, and T. Deutsch, "Picosecond Optical Breakdown: Tissue Effects and Reduction of Collateral Damage", Lasers in Surgery and Medicine 9:192-204 (1989).*|
|5||C. LeBlanc, "Realization and Characterization of a High Intensity Femtosecond Laser System Based on all Titanium Doped Sapphire", Annales de Physique, vol. 19, No. 1, Abstract, Feb. 1994.*|
|6||C.V. Shank and M.C. Downer, "Femtosecond Dynamics of Highly Excited Semiconductors", Mat. Res. Soc. Symp. Proc., vol. 51, 15-23, 1985.*|
|7||C.V. Shank, R. Yen and C. Hirlimann, "Time Resolved Reflectivity Measures of Femtosecond-Optical-Pulse-Induced Phase transitions in Silicon", Physical Review Letters, vol. 50, No. 6, 454-457, Feb. 7, 1983.*|
|8||C.V. Shank, R. Yen, and C. Hirlimann, "Femtosecond-Time Resolved Surface Structural Dynamics of Optically Excited Silicon", Physical Review Letters, vol. 51, No. 10, 900-902, Sep. 5, 1983.*|
|9||*||D. Du, X. Lin, G. Korn, J. Squier, and G. Morou, "Laser-Induced Breakdown by Impact Ionization in SiO2 with Pulse Widths from 7 ns to 150 fs", Appl. Phys. letters 64 (23), (Jun. 6, 1994).|
|10||D. Stern, R. Schoenlein, C. Puliafito, E. Dobi, R. Birngruber and J. Fujimoto, "Corneal Ablation by Nanosecond, Picosecond, and Femtosecond Lasers at 532 and 625 nm", Arch Opthalmol, vol. 107, (Apr. 1989).*|
|11||D.H. Reitzke, X. Wang, H. Ahn, and M.C. Downer, "Femtosecond Laser Melting of Graphite", Physical Review B, vol. 40, No. 17, Dec. 15, 1989.*|
|12||F. Muller, K. Mann, R. Simon, J.S. Bernstein, and G.J. Zaal, "A comparative Study of Decomposition of Thin Films by Laser Induced PVD with Femtosecond and Nanosecond Laser Pulses", SPIE vol. 1858, pp. 464-475, 1993.*|
|13||G. Mourou, A. Zewail, P. Barbara, and W. Knox, "New Generation of Ultrafast Sources Marked by Higher Powers, Versatility" Optics & Photonics News (Mar. 1994).*|
|14||G.L. LeCarpentier et al. "Continuous Wave Laser Ablation of Tissue: Analysis of Thermal and Mechanical Events", IEEE Transactions on Biomedical Engineering, vol. 40, No. 2, 188-200, Feb. 1993.*|
|15||H. Cooper, J. Schuman, C. Puliafito, D. McCarthy, W. Woods, N. Friedmann, N. Wang, and C. Lin, "Picosecond Neodymium:Yttrium Lithium Fluoride Laser Sclerectomy", Am. Journal of Opth. 115:221-224, (Feb. 1993).*|
|16||H. Kapteyn and M. Murnane, "Femtosecond Lasers: The next Generation", Optics & Photonics News, (Mar. 1994).*|
|17||International Search Report Form PCT/ISO/210 Dated Jul. 31, 1995 and Mailed Aug. 4, 1995.*|
|18||J. Squier and G. Mourou, "Tunable Solid State Lasers Create Ultrashort Pulses", Laser Focus World, (Jun. 1992).*|
|19||J. Squier, F. Salin, and G. Mourou, "100-fs Pulse Generation and Amplification in TiAl2O3", Optics letters, vol. 16, No. 5 (Mar. 1991).*|
|20||K. Frederickson, W. White, R. Wheeland, and D. Slaughter, "Precise Ablation of Skin with Reduced Collateral Damage Using the Femtosecond-Pulsed, Terawatt Titanium-Sapphire Laser", Arch Dermatol, vol. 129, (Aug. 1993).*|
|21||M.H. Niemz, T.P. Hoppeler, T. Juhasz, and J. Bille, "Intrastromal Ablations for Refractive Corneal Surgery Using Picosecond Infrared Laser Pulses", Lasers and Light in Opthamology, vol. 5, No. 3, pp. 149-155, 1993.*|
|22||M.W. Berns et al., "Laser Microsurgery in Cell and Developmental Biology", Science, vol. 213, No. 31, pp. 505-513, Jul. 1981.*|
|23||N. Bloembergen, "Laser-Induced Electric Breakdown in Solids", IEEE Journal of Quantum ELectronics, vol. QE-10, No. 3, (Mar. 1974).*|
|24||R. Birngruber, C. Puliafito, A. Gawande, W. Lin, R. Schoenlein, and J. Fujimoto, "Femtosecond Laser-Tissue Interactions: Retinal Injury Studies", IEEE Journal of Quantum Electronics, vol. QE-23, No. 10, 1836-1844, Oct. 1987.*|
|25||R. Birngruber, C. Puliafito, A. Gawande, W. Lin, R. Schoenlein, and J. Fujimoto, Femtosecond Laser-Tissue Interactions: Retinal Injury Studies, IEEE Log. No. 8716039, (1987).*|
|26||R. Remmel, C. Dardenne, and J. Bille, "Intrasomal Tissue Removed Using an Infrared Picosecond Nd:YLF Opthalmic Laser Operating at 1053 nm", Lasers and Light in Opthamology, vol. 4, No. 3/4, 169-173, (1992).*|
|27||S. Küper and M. Stuke, "Femtosecond uv Excimer Laser Ablation", Applied Physics B, vol. 44, 199-201, Jun. 7, 1993.*|
|28||S. Preuss, M. Späth, Y. Zhang, and M. Stuke, "Time Resolved Dynamics of Subpicosecond Laser Ablation", Applied Physics Letters, vol. 62, No. 23, 3049-3051, Jun. 7, 1993.*|
|29||S. Watanabe, R. Anderson, S. Brorson, G. Dalickas, J. Fujimoto, and T. Flotte, "Comparative Studies of Femtosecond to Microsecond Laser Pulses on Selective Pigmented Cell Injury in Skin", Photochemistry and Photobiology vol. 53, No. 6, 757-762, 1991.*|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US6489589 *||Mar 5, 1998||Dec 3, 2002||Board Of Regents, University Of Nebraska-Lincoln||Femtosecond laser utilization methods and apparatus and method for producing nanoparticles|
|US6852946||Dec 20, 2002||Feb 8, 2005||Caterpillar Inc||Laser-induced plasma micromachining|
|US6979798||Feb 26, 2004||Dec 27, 2005||Gsi Lumonics Corporation||Laser system and method for material processing with ultra fast lasers|
|US6995336||Jan 26, 2004||Feb 7, 2006||The Regents Of The University Of Michigan||Method for forming nanoscale features|
|US7143769||Aug 11, 2004||Dec 5, 2006||Richard Stoltz||Controlling pulse energy of an optical amplifier by controlling pump diode current|
|US7169687||Nov 3, 2004||Jan 30, 2007||Intel Corporation||Laser micromachining method|
|US7349452||Apr 22, 2005||Mar 25, 2008||Raydiance, Inc.||Bragg fibers in systems for the generation of high peak power light|
|US7361171||Aug 11, 2004||Apr 22, 2008||Raydiance, Inc.||Man-portable optical ablation system|
|US7367969||Aug 11, 2004||May 6, 2008||Raydiance, Inc.||Ablative material removal with a preset removal rate or volume or depth|
|US7391557 *||Mar 26, 2004||Jun 24, 2008||Applied Photonics Worldwide, Inc.||Mobile terawatt femtosecond laser system (MTFLS) for long range spectral sensing and identification of bioaerosols and chemical agents in the atmosphere|
|US7474919||Aug 8, 2003||Jan 6, 2009||The Regents Of The University Of Michigan||Laser-based method and system for enhancing optical breakdown|
|US7486705||Mar 31, 2004||Feb 3, 2009||Imra America, Inc.||Femtosecond laser processing system with process parameters, controls and feedback|
|US7560658||Jun 27, 2005||Jul 14, 2009||The Regents Of The University Of Michigan||Method for forming nanoscale features|
|US7584756||Aug 17, 2004||Sep 8, 2009||Amo Development, Llc||Apparatus and method for correction of aberrations in laser system optics|
|US7611966 *||Nov 3, 2009||Intel Corporation||Dual pulsed beam laser micromachining method|
|US7671295||Mar 2, 2010||Electro Scientific Industries, Inc.||Processing a memory link with a set of at least two laser pulses|
|US7679030||Jan 4, 2008||Mar 16, 2010||Gsi Group Corporation||Energy-efficient, laser-based method and system for processing target material|
|US7723642||Oct 10, 2003||May 25, 2010||Gsi Group Corporation||Laser-based system for memory link processing with picosecond lasers|
|US7750268||Jul 6, 2010||Gsi Group Corporation||Energy efficient, laser-based method and system for processing target material|
|US7767272||May 25, 2007||Aug 3, 2010||Imra America, Inc.||Method of producing compound nanorods and thin films|
|US7838794||Nov 23, 2010||Gsi Group Corporation||Laser-based method and system for removing one or more target link structures|
|US7887532||Feb 15, 2011||Amo Development, Llc.||System and method for resecting corneal tissue using non-continuous initial incisions|
|US7912100||Dec 19, 2008||Mar 22, 2011||Imra America, Inc.||Femtosecond laser processing system with process parameters, controls and feedback|
|US7955905||Jun 7, 2011||Gsi Group Corporation||Methods and systems for thermal-based laser processing a multi-material device|
|US7955906||Jul 1, 2008||Jun 7, 2011||Gsi Group Corporation||Methods and systems for thermal-based laser processing a multi-material device|
|US7970026||Dec 30, 2009||Jun 28, 2011||Ekspla Ltd.||Multiple output repetitively pulsed laser|
|US8029501||Dec 30, 2005||Oct 4, 2011||Attodyne Inc.||Laser selective cutting by impulsive heat deposition in the IR wavelength range for direct-drive ablation|
|US8125704||Aug 18, 2008||Feb 28, 2012||Raydiance, Inc.||Systems and methods for controlling a pulsed laser by combining laser signals|
|US8139910||Oct 27, 2008||Mar 20, 2012||Raydiance, Inc.||Systems and methods for control of ultra short pulse amplification|
|US8150271||Sep 21, 2010||Apr 3, 2012||Raydiance, Inc.||Active tuning of temporal dispersion in an ultrashort pulse laser system|
|US8168961||May 1, 2012||Fei Company||Charged particle beam masking for laser ablation micromachining|
|US8173929||May 8, 2012||Raydiance, Inc.||Methods and systems for trimming circuits|
|US8189971||May 29, 2012||Raydiance, Inc.||Dispersion compensation in a chirped pulse amplification system|
|US8217304||Mar 27, 2002||Jul 10, 2012||Gsi Group Corporation||Methods and systems for thermal-based laser processing a multi-material device|
|US8231612||Nov 19, 2007||Jul 31, 2012||Amo Development Llc.||Method of making sub-surface photoalterations in a material|
|US8232687||Apr 26, 2007||Jul 31, 2012||Raydiance, Inc.||Intelligent laser interlock system|
|US8246609||Aug 21, 2012||Amo Development, Llc.||Intracorneal inlay, system, and method|
|US8253066||Aug 28, 2012||Gsi Group Corporation||Laser-based method and system for removing one or more target link structures|
|US8279903||Feb 11, 2011||Oct 2, 2012||Imra America, Inc.||Femtosecond laser processing system with process parameters, controls and feedback|
|US8292877||Feb 20, 2012||Oct 23, 2012||Amo Development, Llc.||System and method for incising material|
|US8338746||Feb 12, 2010||Dec 25, 2012||Electro Scientific Industries, Inc.||Method for processing a memory link with a set of at least two laser pulses|
|US8350183 *||Jun 7, 2008||Jan 8, 2013||Universitat Zu Lubeck||Method for laser machining transparent materials|
|US8357196||Nov 18, 2009||Jan 22, 2013||Abbott Medical Optics Inc.||Mark for intraocular lenses|
|US8388609||Dec 1, 2008||Mar 5, 2013||Amo Development, Llc.||System and method for multibeam scanning|
|US8394084||Mar 12, 2013||Optimedica Corporation||Apparatus for patterned plasma-mediated laser trephination of the lens capsule and three dimensional phaco-segmentation|
|US8398622||Dec 6, 2010||Mar 19, 2013||Raydiance, Inc.||Portable optical ablation system|
|US8403921||Aug 16, 2012||Mar 26, 2013||Optimedica Corporation||Method and apparatus for patterned plasma-mediated laser trephination of the lens capsule and three dimensional phaco-segmentation|
|US8425497||Mar 25, 2011||Apr 23, 2013||Optimedica Corporation||Method and apparatus for patterned plasma-mediated laser trephination of the lens capsule and three dimensional phaco-segmentation|
|US8461478||Feb 3, 2010||Jun 11, 2013||Abbott Cardiovascular Systems, Inc.||Multiple beam laser system for forming stents|
|US8498538||Nov 13, 2009||Jul 30, 2013||Raydiance, Inc.||Compact monolithic dispersion compensator|
|US8500724||Mar 25, 2011||Aug 6, 2013||Optimedica Corporation||Method and apparatus for patterned plasma-mediated laser trephination of the lens capsule and three dimensional phaco-segmentation|
|US8518026||Mar 13, 2008||Aug 27, 2013||Optimedica Corporation||Apparatus for creating incisions to improve intraocular lens placement|
|US8524139||Jun 30, 2010||Sep 3, 2013||FEI Compay||Gas-assisted laser ablation|
|US8530783||Feb 3, 2010||Sep 10, 2013||Abbott Cardiovascular Systems Inc.||Laser cutting system|
|US8556511||Sep 8, 2010||Oct 15, 2013||Abbott Cardiovascular Systems, Inc.||Fluid bearing to support stent tubing during laser cutting|
|US8568478||Sep 21, 2006||Oct 29, 2013||Abbott Medical Optics Inc.||Intraocular lenses for managing glare, adhesion, and cell migration|
|US8609205||Jul 2, 2009||Dec 17, 2013||Imra America, Inc.||Method for depositing crystalline titania nanoparticles and films|
|US8619357||Feb 1, 2011||Dec 31, 2013||Raydiance, Inc.||Static phase mask for high-order spectral phase control in a hybrid chirped pulse amplifier system|
|US8629416||Apr 18, 2012||Jan 14, 2014||Fei Company||Charged particle beam masking for laser ablation micromachining|
|US8644356||Sep 12, 2012||Feb 4, 2014||Imra America, Inc.||Femtosecond laser processing system with process parameters controls and feedback|
|US8657810||Feb 10, 2010||Feb 25, 2014||Optimedica Corporation||Method for creating incisions to improve intraocular lens placement|
|US8663208||Feb 9, 2010||Mar 4, 2014||Amo Development, Llc||System and method for intrastromal refractive correction|
|US8685006||Nov 9, 2007||Apr 1, 2014||Carl Zeiss Meditec Ag||Treatment apparatus for surgical correction of defective eyesight, method of generating control data therefore, and method for surgical correction of defective eyesight|
|US8690862||Mar 13, 2013||Apr 8, 2014||Optimedica Corporation||Apparatus for patterned plasma-mediated laser trephination of the lens capsule and three dimensional phaco-segmentation|
|US8709001||Aug 17, 2012||Apr 29, 2014||Optimedica Corporation|
|US8764736||Sep 5, 2008||Jul 1, 2014||Alcon Lensx, Inc.||Laser-induced protection shield in laser surgery|
|US8809734||Jul 3, 2012||Aug 19, 2014||Electron Scientific Industries, Inc.||Methods and systems for thermal-based laser processing a multi-material device|
|US8842358||Aug 1, 2013||Sep 23, 2014||Gentex Corporation||Apparatus, method, and process with laser induced channel edge|
|US8852175||Nov 21, 2008||Oct 7, 2014||Amo Development Llc||Apparatus, system and method for precision depth measurement|
|US8853592||Jul 9, 2009||Oct 7, 2014||Fei Company||Method for laser machining a sample having a crystalline structure|
|US8872062||Feb 3, 2010||Oct 28, 2014||Abbott Cardiovascular Systems Inc.||Laser cutting process for forming stents|
|US8884184||Aug 11, 2011||Nov 11, 2014||Raydiance, Inc.||Polymer tubing laser micromachining|
|US8901452||Jun 10, 2013||Dec 2, 2014||Abbott Cardiovascular Systems, Inc.||Multiple beam laser system for forming stents|
|US8921733||Apr 13, 2012||Dec 30, 2014||Raydiance, Inc.||Methods and systems for trimming circuits|
|US8968375||Feb 8, 2010||Mar 3, 2015||Optimedica Corporation||Method for patterned plasma-mediated modification of the crystalline lens|
|US9006604||Jun 10, 2013||Apr 14, 2015||Abbott Cardiovascular Systems Inc.||Multiple beam laser system for forming stents|
|US9022037||Sep 12, 2005||May 5, 2015||Raydiance, Inc.||Laser ablation method and apparatus having a feedback loop and control unit|
|US9095415||Feb 19, 2014||Aug 4, 2015||Optimedica Corporation|
|US9101446||Mar 11, 2013||Aug 11, 2015||Intralase Corp.||System and method for scanning a pulsed laser beam|
|US9101448||Feb 19, 2014||Aug 11, 2015||Optimedica Corporation|
|US9107732||Feb 19, 2014||Aug 18, 2015||Optimedica Corporation|
|US9108270||Jan 2, 2008||Aug 18, 2015||Amo Development, Llc||System and method for scanning a pulsed laser beam|
|US9114482||Sep 16, 2011||Aug 25, 2015||Raydiance, Inc.||Laser based processing of layered materials|
|US9119703||Oct 17, 2014||Sep 1, 2015||Optimedica Corporation|
|US9119704||Oct 17, 2014||Sep 1, 2015||Optimedica Corporation|
|US9125725||Oct 17, 2014||Sep 8, 2015||Optimedica Corporation|
|US9130344||Jan 30, 2009||Sep 8, 2015||Raydiance, Inc.||Automated laser tuning|
|US9138351||Mar 17, 2015||Sep 22, 2015||Amo Development, Llc||Method for scanning a pulsed laser beam|
|US9147989||Dec 9, 2013||Sep 29, 2015||Imra America, Inc.||Femtosecond laser processing system with process parameters controls and feedback|
|US9199334||Apr 1, 2015||Dec 1, 2015||Abbott Cardiovascular Systems Inc.||Multiple beam laser system for forming stents|
|US9226853||Mar 17, 2015||Jan 5, 2016||Amo Development, Llc||Method for scanning a pulsed laser beam|
|US9233023||Mar 13, 2008||Jan 12, 2016||Optimedica Corporation||Method and apparatus for creating ocular surgical and relaxing incisions|
|US9233024||Aug 7, 2012||Jan 12, 2016||Optimedica Corporation||Method and apparatus for creating ocular surgical and relaxing incisions|
|US9271870||Jun 17, 2015||Mar 1, 2016||Optimedica Corporation||Apparatus for patterned plasma-mediated laser ophthalmic surgery|
|US9281653||Jul 19, 2012||Mar 8, 2016||Coherent, Inc.||Intelligent laser interlock system|
|US9295518||Jul 14, 2010||Mar 29, 2016||Koninklijke Philips N.V.||Optical blade and hair cutting device|
|US9359252||Jul 24, 2015||Jun 7, 2016||Corning Incorporated||Methods for controlled laser-induced growth of glass bumps on glass articles|
|US9364317||Feb 10, 2010||Jun 14, 2016||Optimedica Corporation||Method for creating incisions to improve intraocular lens placement|
|US9370445||Feb 17, 2014||Jun 21, 2016||Carl Zeiss Meditec Ag||Treatment apparatus for surgical correction of defective eyesight, method of generating control data therefore, and method for surgical correction of defective eyesight|
|US20020167581 *||Mar 27, 2002||Nov 14, 2002||Cordingley James J.||Methods and systems for thermal-based laser processing a multi-material device|
|US20030062126 *||Sep 30, 2002||Apr 3, 2003||Scaggs Michael J.||Method and apparatus for assisting laser material processing|
|US20030151053 *||Dec 17, 2002||Aug 14, 2003||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20030222324 *||Apr 24, 2003||Dec 4, 2003||Yunlong Sun||Laser systems for passivation or link processing with a set of laser pulses|
|US20040118823 *||Dec 20, 2002||Jun 24, 2004||Groen Cale E.||Laser-induced plasma micromachining|
|US20040134894 *||Oct 10, 2003||Jul 15, 2004||Bo Gu||Laser-based system for memory link processing with picosecond lasers|
|US20040134896 *||Oct 10, 2003||Jul 15, 2004||Bo Gu||Laser-based method and system for memory link processing with picosecond lasers|
|US20040188399 *||Apr 6, 2004||Sep 30, 2004||Gsi Lumonics Inc.||Energy-efficient, laser-based method and system for processing target material|
|US20040226925 *||Feb 26, 2004||Nov 18, 2004||Bo Gu||Laser system and method for material processing with ultra fast lasers|
|US20050064137 *||Nov 11, 2004||Mar 24, 2005||Hunt Alan J.||Method for forming nanoscale features and structures produced thereby|
|US20050065502 *||May 19, 2004||Mar 24, 2005||Richard Stoltz||Enabling or blocking the emission of an ablation beam based on color of target|
|US20050074974 *||Oct 1, 2004||Apr 7, 2005||Richard Stoltz||Semiconductor manufacturing using optical ablation|
|US20050171516 *||Aug 11, 2004||Aug 4, 2005||Richard Stoltz||Man-portable optical ablation system|
|US20050195726 *||Feb 8, 2005||Sep 8, 2005||Jeff Bullington||Semiconductor-type processing for solid-state lasers|
|US20050199599 *||Mar 9, 2004||Sep 15, 2005||Xinghua Li||Method of fabrication of hermetically sealed glass package|
|US20050215985 *||Feb 13, 2005||Sep 29, 2005||Michael Mielke||Method of generating an ultra-short pulse using a high-frequency ring oscillator|
|US20050226287 *||Mar 31, 2004||Oct 13, 2005||Imra America, Inc.||Femtosecond laser processing system with process parameters, controls and feedback|
|US20050236380 *||Jun 9, 2005||Oct 27, 2005||Olympus Corporation||Ultrashort pulse laser processing method|
|US20060054604 *||Sep 10, 2004||Mar 16, 2006||Saunders Richard J||Laser process to produce drug delivery channel in metal stents|
|US20060064079 *||Aug 11, 2004||Mar 23, 2006||Richard Stoltz||Ablative material removal with a preset removal rate or volume or depth|
|US20060086702 *||Dec 19, 2005||Apr 27, 2006||Gsi Group Corp||Energy-efficient, laser-based method and system for processing target material|
|US20060091125 *||Nov 3, 2004||May 4, 2006||Intel Corporation||Laser micromachining method|
|US20060126679 *||Apr 22, 2005||Jun 15, 2006||Brennan James F Iii||Bragg fibers in systems for the generation of high peak power light|
|US20060131284 *||Nov 23, 2005||Jun 22, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060131285 *||Nov 23, 2005||Jun 22, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060131286 *||Nov 30, 2005||Jun 22, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060131287 *||Nov 30, 2005||Jun 22, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060131288 *||Nov 30, 2005||Jun 22, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060134838 *||Nov 23, 2005||Jun 22, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060138096 *||Nov 30, 2005||Jun 29, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060138106 *||Feb 21, 2006||Jun 29, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060138107 *||Feb 22, 2006||Jun 29, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060138108 *||Feb 22, 2006||Jun 29, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060138109 *||Feb 22, 2006||Jun 29, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060138110 *||Feb 22, 2006||Jun 29, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060140230 *||Feb 21, 2006||Jun 29, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060141680 *||Feb 21, 2006||Jun 29, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060141681 *||Feb 22, 2006||Jun 29, 2006||Yunlong Sun||Processing a memory link with a set of at least two laser pulses|
|US20060191884 *||Jan 18, 2006||Aug 31, 2006||Johnson Shepard D||High-speed, precise, laser-based material processing method and system|
|US20060192845 *||May 2, 2006||Aug 31, 2006||Gsi Lumonics Corporation||Methods and systems for thermal-based laser processing a multi-material device|
|US20060195076 *||Jan 9, 2006||Aug 31, 2006||Blumenkranz Mark S|
|US20060237405 *||Jun 27, 2005||Oct 26, 2006||The Regents Of The University Of Michigan||Method for forming nanoscale features|
|US20060249816 *||May 5, 2005||Nov 9, 2006||Intel Corporation||Dual pulsed beam laser micromachining method|
|US20070000875 *||Sep 11, 2006||Jan 4, 2007||Coherent, Inc.||Method and apparatus for assisting laser material processing|
|US20070052791 *||Nov 7, 2006||Mar 8, 2007||Gsi Lumonics Corporation||Methods and systems for thermal-based laser processing a multi-material device|
|US20070064304 *||Sep 22, 2005||Mar 22, 2007||Brennan James Francis Iii||Wavelength-stabilized pump diodes for pumping gain media in an ultrashort pulsed laser system|
|US20070110354 *||Nov 16, 2005||May 17, 2007||Raydiance, Inc.||Method and apparatus for optical isolation in high power fiber-optic systems|
|US20070199927 *||Jan 31, 2007||Aug 30, 2007||Bo Gu||Laser-based method and system for removing one or more target link structures|
|US20070253455 *||Apr 26, 2007||Nov 1, 2007||Stadler Andrew D||Intelligent Laser Interlock System|
|US20080017010 *||Jul 31, 2007||Jan 24, 2008||Advanced Cardiovascular Systems, Inc.||Laser process to produce drug delivery channel in metal stents|
|US20080058777 *||Sep 5, 2006||Mar 6, 2008||Intralase Corp.||System and method for resecting corneal tissue using non-continuous initial incisions|
|US20080058841 *||Sep 5, 2006||Mar 6, 2008||Kurtz Ronald M||System and method for marking corneal tissue in a transplant procedure|
|US20080077238 *||Sep 21, 2006||Mar 27, 2008||Advanced Medical Optics, Inc.||Intraocular lenses for managing glare, adhesion, and cell migration|
|US20080077239 *||Sep 21, 2006||Mar 27, 2008||Advanced Medical Optics, Inc.||Intraocular lenses for managing glare, adhesion, and cell migration|
|US20080105663 *||Oct 30, 2007||May 8, 2008||The Regents Of The University Of Michigan||Method for forming nanoscale features and structures produced thereby|
|US20080140060 *||Feb 7, 2008||Jun 12, 2008||Raydiance, Inc.||Ablative material removal with a preset removal rate or volume or depth|
|US20080180655 *||Mar 26, 2004||Jul 31, 2008||Applied Photonics Worldwide, Inc.||Mobile terawatt femtosecond laser system (mtfls) for long range spectral sensing and identification of bioaerosols and chemical agents in the atmosphere|
|US20080187684 *||May 10, 2007||Aug 7, 2008||Imra America, Inc.||Method for depositing crystalline titania nanoparticles and films|
|US20080281413 *||Mar 13, 2008||Nov 13, 2008||William Culbertson||Method and apparatus for creating incisions to improve intraocular lens placement|
|US20080284837 *||Jul 1, 2008||Nov 20, 2008||Gsi Group Corporation||Methods and systems for therma-based laser processing a multi-material device|
|US20080319428 *||Nov 9, 2007||Dec 25, 2008||Carl Zeiss Meditec Ag||Treatment apparatus for surgical correction of defective eyesight, method of generating control data therefore, and method for surgical correction of defective eyesight|
|US20090012507 *||Mar 13, 2008||Jan 8, 2009||William Culbertson||Method for patterned plasma-mediated modification of the crystalline lens|
|US20090045179 *||Aug 15, 2007||Feb 19, 2009||Ellen Marie Kosik Williams||Method and system for cutting solid materials using short pulsed laser|
|US20090097514 *||Dec 19, 2008||Apr 16, 2009||Imra America, Inc.||Femtosecond laser processing system with process parameters, controls and feedback|
|US20090118716 *||Nov 7, 2007||May 7, 2009||Intralase, Inc.||System and method for scanning a pulsed laser beam|
|US20090126870 *||Nov 19, 2007||May 21, 2009||Advanced Medical Optics, Inc.||Method of making sub-surface photoalterations in a material|
|US20090137988 *||Oct 31, 2008||May 28, 2009||Lensx Lasers, Inc||Methods And Apparatus For Improved Post-Operative Ocular Optical Performance|
|US20090137991 *||Sep 18, 2008||May 28, 2009||Kurtz Ronald M||Methods and Apparatus for Laser Treatment of the Crystalline Lens|
|US20090137993 *||Sep 18, 2008||May 28, 2009||Kurtz Ronald M||Methods and Apparatus for Integrated Cataract Surgery|
|US20090143772 *||Sep 5, 2008||Jun 4, 2009||Kurtz Ronald M||Laser-Induced Protection Shield in Laser Surgery|
|US20090149840 *||Sep 5, 2008||Jun 11, 2009||Kurtz Ronald M||Photodisruptive Treatment of Crystalline Lens|
|US20090149841 *||Sep 10, 2008||Jun 11, 2009||Kurtz Ronald M||Effective Laser Photodisruptive Surgery in a Gravity Field|
|US20090171327 *||Dec 23, 2008||Jul 2, 2009||Lensx Lasers, Inc.||Photodisruptive Laser Treatment of the Crystalline Lens|
|US20090177189 *||Jan 9, 2009||Jul 9, 2009||Ferenc Raksi||Photodisruptive laser fragmentation of tissue|
|US20090213879 *||Jan 30, 2009||Aug 27, 2009||Stadler Andrew D||Automated Laser Tuning|
|US20090247997 *||Apr 1, 2009||Oct 1, 2009||Amo Development, Llc||Ophthalmic laser apparatus, system, and method with high resolution imaging|
|US20090247998 *||Apr 1, 2009||Oct 1, 2009||Amo Development, Llc||System and method of iris-pupil contrast enhancement|
|US20090247999 *||Apr 1, 2009||Oct 1, 2009||Amo Development, Llc||Corneal implant system, interface, and method|
|US20090281530 *||Jun 12, 2006||Nov 12, 2009||Technolas Perfect Vision Gmbh Messerschmittstrasse 1+3||Method for treating an organic material|
|US20090289382 *||May 22, 2008||Nov 26, 2009||Raydiance, Inc.||System and method for modifying characteristics of a contact lens utilizing an ultra-short pulsed laser|
|US20090311513 *||Jul 2, 2009||Dec 17, 2009||Imra America, Inc.||Method for depositing crystalline titania nanoparticles and films|
|US20090323740 *||Dec 31, 2009||Stadler Andrew D||Systems And Methods For Control Of Ultra Short Pulse Amplification|
|US20090326650 *||Dec 31, 2009||Amo Development, Llc||Intracorneal inlay, system, and method|
|US20100038825 *||Dec 21, 2007||Feb 18, 2010||Mcdonald Joel P||Methods of forming microchannels by ultrafast pulsed laser direct-write processing|
|US20100040095 *||Aug 18, 2008||Feb 18, 2010||Raydiance, Inc.||Systems and methods for controlling a pulsed laser by combining laser signals|
|US20100127190 *||Nov 26, 2008||May 27, 2010||Fei Company||Charged particle beam masking for laser ablation micromachining|
|US20100130966 *||Nov 21, 2008||May 27, 2010||Advanced Medical Optics, Inc.||Apparatus, System and Method for Precision Depth Measurement|
|US20100133246 *||Dec 1, 2008||Jun 3, 2010||Amo Development, Llc||System and method for multibeam scanning|
|US20100135341 *||Dec 30, 2009||Jun 3, 2010||Ekspla Ltd.||Multiple Output Repetitively Pulsed Laser|
|US20100163540 *||Jun 7, 2008||Jul 1, 2010||Universitat Zu Lubeck||Method for Laser Machining Transparent Materials|
|US20100191226 *||Jul 27, 2009||Jul 29, 2010||Optimedica Corporation||Method Of Patterned Plasma-Mediated Laser Trephination Of The Lens Capsule And Three Dimensional Phaco-Segmentation|
|US20100193482 *||Feb 3, 2010||Aug 5, 2010||Abbott Cardiovascular Systems Inc.||laser cutting system|
|US20100193483 *||Feb 3, 2010||Aug 5, 2010||Abbott Cardiovascular Systems Inc.||Laser cutting process for forming stents|
|US20100193484 *||Feb 3, 2010||Aug 5, 2010||Abbott Cardiovascular Systems Inc.||Multiple beam laser system for forming stents|
|US20100209700 *||Aug 19, 2010||Imra America, Inc.||Method of producing compound nanorods and thin films|
|US20100256965 *||Mar 25, 2010||Oct 7, 2010||Christian Rathjen||System for defining cuts in eye tissue|
|US20100331829 *||Dec 18, 2009||Dec 30, 2010||Amo Development, Llc.||System and method for multi-beam scanning|
|US20110031655 *||Jun 30, 2010||Feb 10, 2011||Fei Company||Gas-assisted laser ablation|
|US20110073584 *||Dec 6, 2010||Mar 31, 2011||Richard Stoltz||Portable Optical Ablation System|
|US20110118836 *||May 19, 2011||Abbott Medical Optics Inc.||Mark for intraocular lenses|
|US20110139760 *||Jun 16, 2011||Imra America, Inc.||Femtosecond laser processing system with process parameters controls and feedback|
|US20110178511 *||Jul 21, 2011||Blumenkranz Mark S|
|US20110178512 *||Jul 21, 2011||Blumenkranz Mark S|
|US20110184392 *||Jul 28, 2011||William Culbertson||Method for patterned plasma-mediated modification of the crystalline lens|
|US20120103945 *||Jul 8, 2009||May 3, 2012||Fei Company||Method And Apparatus For Laser Machining|
|EP1430987A1 *||Nov 19, 2003||Jun 23, 2004||Caterpillar Inc.||Laser-induced plasma micromachining|
|EP1674189A1 *||Oct 8, 2004||Jun 28, 2006||Olympus Corporation||Ultrashort pulse laser processing method|
|EP2191927A1||Nov 25, 2009||Jun 2, 2010||FEI Company||Method of and system for forming a microscopic structure on a substrate using a mask formed on this substrate|
|EP2236109A1 *||Apr 2, 2009||Oct 6, 2010||SIE AG, Surgical Instrument Engineering||System for defining cuts in eye tissue|
|EP2283960A1||Aug 4, 2010||Feb 16, 2011||FEI Company||Gas-assisted laser ablation|
|EP2477568B1 *||Aug 18, 2010||Mar 30, 2016||Lumera Laser GmbH||Laser beam aligning unit and laser treatment device for treating a material|
|EP2671970A1||Jan 31, 2008||Dec 11, 2013||Imra America, Inc.||A method for depositing crystalline titania nanoparticles and films|
|EP2700470A1||Aug 4, 2010||Feb 26, 2014||Fei Company||Gas-assisted laser ablation|
|EP2772333A1 *||Dec 30, 2005||Sep 3, 2014||Attodyne Inc.||Laser selective cutting by impulsive heat deposition in the ir wavelength range for direct-drive ablation|
|EP2926769A1||Jun 29, 2009||Oct 7, 2015||AMO Development, LLC||Intracorneal inlay, system, and method|
|EP2965706A1 *||Aug 31, 2009||Jan 13, 2016||Starmedtec GmbH||Multifunctional laser device|
|EP3001944A1||Jun 22, 2012||Apr 6, 2016||AMO Development, LLC||Ophthalmic range finding|
|WO2002090036A1 *||May 9, 2002||Nov 14, 2002||Vanderbilt University||Method and apparatus for laser ablative modification of dielectric surfaces|
|WO2005123324A1||Jun 8, 2005||Dec 29, 2005||Tag Heuer Sa||Method of producing a micro- or nano-mechanical part, comprising a femto-laser-assisted ablation step|
|WO2006069448A2 *||Dec 30, 2005||Jul 6, 2006||Miller R J Dwayne||Laser selective cutting by impulsive heat deposition in the ir wavelength range for direct-drive ablation|
|WO2006069448A3 *||Dec 30, 2005||Mar 22, 2007||R J Dwayne Miller||Laser selective cutting by impulsive heat deposition in the ir wavelength range for direct-drive ablation|
|WO2008030698A2||Aug 20, 2007||Mar 13, 2008||Amo Development, Llc||System and method for resecting corneal tissue|
|WO2008030718A2||Aug 24, 2007||Mar 13, 2008||Amo Development, Llc||System and method for marking corneal tissue in a transplant procedure|
|WO2008036671A1||Sep 18, 2007||Mar 27, 2008||Advanced Medical Optics, Inc.||Intraocular lenses for managing glare, adhesion, and cell migration|
|WO2008118533A2||Jan 31, 2008||Oct 2, 2008||Imra America, Inc.||A method for depositing crystalline titania nanoparticles and films|
|WO2010022985A1 *||Aug 31, 2009||Mar 4, 2010||Starmedtec Gmbh||Multifunctional laser device|
|WO2010036859A1||Sep 25, 2009||Apr 1, 2010||Amo Development Llc||Laser modification of intraocular lens|
|WO2010091419A1||Feb 9, 2010||Aug 12, 2010||Amo Development Llc.||System and method for intrastromal refractive correction|
|WO2011032551A2 *||Aug 18, 2010||Mar 24, 2011||Lumera Laser Gmbh||Laser beam aligning unit and laser treatment device for treating a material|
|WO2011032551A3 *||Aug 18, 2010||May 26, 2011||Lumera Laser Gmbh||Laser beam aligning unit and laser treatment device for treating a material|
|WO2012178054A1||Jun 22, 2012||Dec 27, 2012||Amo Development, Llc||Ophthalmic range finding|
|WO2013126653A1||Feb 22, 2013||Aug 29, 2013||Amo Development, Llc||Preformed lens systems and methods|
|International Classification||H01S3/00, B23K26/00, B23K26/38, B23K26/40, B23K26/36, A61F9/008, B23K26/06, A61B18/20|
|Cooperative Classification||B23K26/0624, B23K26/0057, B23K2203/50, B23K26/402, B23K26/40, B23K2203/30, B23K2203/08, B23K26/382, B23K26/066, A61B18/20, B23K2201/40, A61F9/00825|
|European Classification||A61F9/008D, B23K26/06C7, B23K26/40A, B23K26/40B11B, B23K26/40B7, B23K26/00G, B23K26/40A2, A61B18/20, B23K26/38B, B23K26/06B4B|
|Jan 28, 2003||AS||Assignment|
Owner name: SILICON VALLEY BANK, CALIFORNIA
Free format text: SECURITY INTEREST;ASSIGNOR:INTRALASE CORP.;REEL/FRAME:013705/0441
Effective date: 20021231
|Aug 17, 2004||RR||Request for reexamination filed|
Effective date: 20040625
|Mar 8, 2005||FPAY||Fee payment|
Year of fee payment: 8
|Mar 8, 2005||SULP||Surcharge for late payment|
Year of fee payment: 7
|Dec 18, 2006||AS||Assignment|
Owner name: INTRALASE CORPORATION, CALIFORNIA
Free format text: RELEASE;ASSIGNOR:SILICON VALLEY BANK;REEL/FRAME:018711/0119
Effective date: 20061208
|Mar 6, 2007||B1||Reexamination certificate first reexamination|
Free format text: CLAIMS 6 AND 11 ARE CANCELLED. CLAIMS 1, 3, 4, 7, 24, 33, 35, 36, 37, 42-44, 46, 48 AND 50-54 ARE DETERMINED TO BE PATENTABLE AS AMENDED. CLAIMS 2, 5, 8-10, 12-23, 25-32, 34, 38-41, 45, 47 AND 49, DEPENDENT ON AN AMENDED CLAIM, ARE DETERMINED TO BE PATENTABLE. NEW CLAIMS 55-64 ARE ADDED AND DETERMINED TO BE PATENTABLE.
|Jan 3, 2008||AS||Assignment|
Owner name: AMO DEVELOPMENT, LLC, CALIFORNIA
Free format text: CHANGE OF NAME;ASSIGNOR:INTRALASE CORP.;REEL/FRAME:020309/0349
Effective date: 20080101
|Feb 22, 2008||AS||Assignment|
Owner name: AMO DEVELOPMENT, LLC, CALIFORNIA
Free format text: CORRECT AN ERROR IN A COVER SHEET PREVIOUSLY RECORDED AT REEL/FRAME 0203009/0349, NAMELY TO DELETE U.S. PATENT NO. 5656186 AND RE37585.;ASSIGNOR:INTRALASE CORP.;REEL/FRAME:020550/0216
Effective date: 20080101
|Mar 20, 2008||AS||Assignment|
Owner name: AMO DEVELOPMENT, LLC, CALIFORNIA
Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE U.S. PATENT NO. 5466233 WAS INCORRECTLY ASSIGNED TO AMO DEVELOPMENT, LLC PREVIOUSLY RECORDED ON REEL 020309 FRAME 0349;ASSIGNOR:INTRALASE CORP.;REEL/FRAME:020679/0026
Effective date: 20080101
|Oct 7, 2008||CC||Certificate of correction|
|Feb 12, 2009||FPAY||Fee payment|
Year of fee payment: 12
|Feb 16, 2009||REMI||Maintenance fee reminder mailed|