Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUSRE42206 E1
Publication typeGrant
Application numberUS 12/421,971
Publication dateMar 8, 2011
Filing dateApr 10, 2009
Priority dateMar 16, 2000
Publication number12421971, 421971, US RE42206 E1, US RE42206E1, US-E1-RE42206, USRE42206 E1, USRE42206E1
InventorsThomas W. Mossberg, Dmitri Iazikov, Christoph M. Greiner
Original AssigneeSteyphi Services De Llc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Multiple wavelength optical source
US RE42206 E1
Abstract
A planar optical waveguide is formed having sets of locking diffractive elements and means for routing optical signals. Lasers are positioned to launch signals into the planar waveguide that are successively incident on elements of the locking diffractive element sets, which route fractions of the signals back to the lasers as locking feedback signals. The routing means route between lasers and output port(s) portions of those fractions of signals transmitted by locking diffractive element sets. Locking diffractive element sets may be formed in channel waveguides formed in the planar waveguide, or in slab waveguide region(s) of the planar waveguide. Multiple routing means may comprise routing diffractive element sets formed in a slab waveguide region of the planar waveguide, or may comprise an arrayed waveguide grating formed in the planar waveguide. The apparatus may comprise a multiple-wavelength optical source.
Images(10)
Previous page
Next page
Claims(51)
1. A method for forming an optical apparatus, comprising:
forming a planar optical waveguide substantially confining in at least one transverse spatial dimension optical signals propagating therein;
forming at least one set of locking diffractive elements in or on the planar optical waveguide;
forming means for routing an optical signal corresponding to at least one said set of locking diffractive elements; and
positioning a laser corresponding to at least one said set of locking diffractive elements so as to launch a corresponding laser optical signal into the planar optical waveguide so that the corresponding laser optical signal is successively incident on the diffractive elements of the corresponding locking diffractive element set,
wherein:
each locking diffractive element set routes within the planar optical waveguide a fraction of the corresponding laser optical signal back to the corresponding laser, with a corresponding locking transfer function, as a corresponding locking optical feedback signal, thereby substantially restricting the corresponding laser optical signal to a corresponding laser operating wavelength range determined at least in part by the corresponding locking transfer function of the corresponding locking diffractive element set; and
each corresponding routing means routes within the planar optical waveguide, between the corresponding laser and a corresponding output optical port with a corresponding routing transfer function, at least a portion of that fraction of the corresponding laser optical signal that is transmitted by the corresponding locking diffractive element set.
2. The method of claim 1, further comprising forming multiple sets of locking diffractive element sets and multiple corresponding routing means, and positioning multiple corresponding lasers so as to launch corresponding laser optical signals into the planar optical waveguide so that the corresponding laser optical signals are successively incident on the diffractive elements of the corresponding locking diffractive element sets.
3. The method of claim 2, wherein the multiple lasers comprise a set of individual lasers each assembled with the planar optical waveguide.
4. The method of claim 2, wherein the multiple lasers comprise an integrated laser array assembled with the planar optical waveguide.
5. The method of claim 2, wherein the multiple lasers are integrated into the planar optical waveguide.
6. The method of claim 5, wherein the planar optical waveguide and the multiple lasers integrated therein comprise semiconductor materials.
7. The method of claim 2, further comprising positioning multiple corresponding monitor photodetectors for receiving portions of the corresponding laser optical signals that propagate out of the planar optical waveguide.
8. The method of claim 7, wherein each locking diffractive element set comprises a corresponding higher-order set of diffractive elements for redirecting a portion of the corresponding laser optical signal to propagate out of the planar optical waveguide and impinge on the corresponding monitor photodetector.
9. The method of claim 7, wherein each routing means comprises a corresponding higher-order set of diffractive elements for redirecting a portion of the corresponding laser optical signal to propagate out of the planar optical waveguide and impinge on the corresponding monitor photodetector.
10. The method of claim 7, further comprising operatively coupling multiple corresponding feedback mechanisms to the corresponding monitor photodetectors for controlling power of the corresponding laser optical signals transmitted by the corresponding locking diffractive element sets.
11. The method of claim 2, further comprising forming multiple corresponding channel optical waveguides in the planar optical waveguide and positioning said corresponding channel waveguides for receiving the corresponding laser optical signals launched from the corresponding lasers into the planar optical waveguide, wherein the corresponding locking diffractive element sets route within the corresponding channel optical waveguides the corresponding fractions of the corresponding laser optical signals back to the corresponding lasers.
12. The method of claim 11, further comprising forming the corresponding channel optical waveguides with tapered or flared end segments for delivering to the corresponding routing means the portions of the corresponding laser optical signals transmitted by the corresponding locking diffractive element sets.
13. The method of claim 2, further comprising forming a slab waveguide region in the planar optical waveguide and positioning said slab waveguide region for receiving the corresponding laser optical signals launched from the corresponding lasers into the planar optical waveguide, wherein the corresponding locking diffractive element sets route within the slab waveguide region the corresponding fractions of the corresponding laser optical signals back to the corresponding lasers.
14. The method of claim 13, further comprising overlaying the corresponding locking diffractive element sets.
15. The method of claim 13, further comprising displacing longitudinally the corresponding locking diffractive element sets relative to one another.
16. The method of claim 13, further comprising interleaving the corresponding locking diffractive element sets.
17. The method of claim 13, further comprising forming the diffractive elements of the multiple locking diffractive sets so as to comprise curvilinear diffractive elements.
18. The method of claim 2, wherein the corresponding laser operating wavelength ranges substantially correspond to operating wavelength channels of a WDM telecommunications system.
19. The method of claim 2, further comprising forming the planar optical waveguide so as to comprise a core and cladding, and forming the diffractive elements of the multiple locking diffractive element sets in the core, in the cladding, on the cladding, or at an interface between the core and the cladding.
20. The method of claim 2, further comprising forming the multiple corresponding routing means:
so as to comprise multiple corresponding routing diffractive element sets formed in a slab optical waveguide region of the planar optical waveguide; and
so that the corresponding fractions of the corresponding laser optical signals transmitted by the corresponding locking diffractive element sets are successively incident on the diffractive elements of the corresponding routing diffractive element sets.
21. The method of claim 20, further comprising overlaying the corresponding routing diffractive element sets.
22. The method of claim 20, further comprising displacing longitudinally the corresponding routing diffractive element sets relative to one another.
23. The method of claim 20, further comprising interleaving the corresponding routing diffractive element sets.
24. The method of claim 20, further comprising forming the corresponding routing diffractive element sets so that the corresponding portions of the multiple corresponding laser optical signals transmitted by the corresponding locking diffractive element sets are routed by the corresponding routing diffractive element sets to a common output optical port.
25. The method of claim 20, further comprising positioning at least one optical fiber for receiving from the planar optical waveguide the corresponding portions of the multiple corresponding laser optical signals transmitted by the corresponding locking diffractive element sets and routed by the corresponding routing diffractive element sets to the corresponding output optical ports.
26. The method of claim 20, further comprising forming the diffractive elements of the multiple routing diffractive sets so as to comprise curvilinear diffractive elements.
27. The method of claim 20, further comprising forming the planar optical waveguide so as to comprise a core and cladding, and forming the diffractive elements of the multiple routing diffractive element sets in the core, in the cladding, on the cladding, or at an interface between the core and the cladding.
28. The method of claim 2, further comprising forming the multiple corresponding routing means so as to comprise an arrayed waveguide grating in the planar optical waveguide.
29. The method of claim 28, further comprising forming the arrayed waveguide grating so as to route the corresponding portions of the multiple corresponding laser optical signals transmitted by the corresponding locking diffractive element sets to a common output optical port.
30. The method of claim 28, further comprising positioning at least one optical fiber for receiving from the planar optical waveguide the corresponding portions of the multiple corresponding laser optical signals transmitted by the corresponding locking diffractive element sets and routed by the arrayed waveguide grating to the corresponding output optical ports.
31. The method of claim 2, further comprising operatively coupling a temperature controller to the planar optical waveguide for maintaining the planar optical waveguide substantially within an operating temperature range.
32. A method of forming an optical apparatus, the method comprising:
forming an optical waveguide;
forming at least a first set of diffractive elements in or on the optical waveguide, wherein each diffractive element of the at least the first set is formed to route, as a corresponding optical feedback signal and within the optical waveguide, a first fraction of a corresponding optical signal incident thereon, and wherein each diffractive element of the at least the first set is further formed to transmit a second fraction of the corresponding optical signal incident thereon; and
forming a second set of diffractive elements, wherein each diffractive element of the second set is formed to route, within the optical waveguide, the corresponding second fraction transmitted by each diffractive element of the at least the first set,
wherein each diffractive element of the at least the first set is further formed to impart a corresponding first transfer function onto the corresponding optical feedback signal to substantially restrict the corresponding optical signal to a corresponding wavelength range determined at least in part by the corresponding first transfer function.
33. The method of claim 32, further comprising positioning an optical source corresponding to the at least the first set of diffractive elements so as to launch the corresponding optical signal into the optical waveguide.
34. The method of claim 33 wherein each diffractive element of the second set is formed to route the corresponding second fraction between the corresponding optical source and a corresponding output optical port, and wherein each diffractive element of the second set is further formed to impart a corresponding second transfer function onto the corresponding second fraction.
35. A method of operating an optical apparatus, the method comprising:
receiving an input optical signal in an optical waveguide;
routing as an optical feedback signal, within the optical waveguide and by at least a first set of diffractive elements formed in or on the optical waveguide, a first fraction of the received input optical signal;
imparting, by the at least the first set of diffractive elements, a first transfer function onto the optical feedback signal to substantially restrict the input optical signal to a wavelength range determined at least in part by the first transfer function;
transmitting, by the at least the first set of diffractive elements, a second fraction of the received optical input signal; and
routing, within the optical waveguide and by a second set of diffractive elements, the transmitted second fraction to an optical port.
36. The method of claim 35, further comprising imparting, by the second set of diffractive elements, a second transfer function onto the second fraction routed to the optical port.
37. The method of claim 35 wherein said receiving the input optical signal includes receiving a plurality of input optical signals from a corresponding plurality of optical sources,
wherein said routing as the optical feedback signal includes routing a plurality of optical feedback signals by a corresponding plurality of the at least the first set of diffractive elements,
wherein said imparting the first transfer function includes imparting, by the corresponding plurality of the at least the first set of diffractive elements, a corresponding plurality of first transfer functions onto the plurality of optical feedback signals to substantially restrict the plurality of input optical signals to corresponding wavelength ranges determined at least in part by the corresponding plurality of first transfer functions.
38. The method of claim 35 wherein said routing the first fraction, by the at least the first set of diffractive elements, includes routing the first fraction within a channel waveguide formed within the optical waveguide, and wherein the at least the first set of diffractive elements is formed within the channel waveguide.
39. An optical apparatus, comprising:
an optical waveguide;
at least a first set of diffractive elements formed in or on the optical waveguide, wherein each diffractive element of the at least the first set is configured to route, as a corresponding optical feedback signal and within the optical waveguide, a first fraction of a corresponding optical signal incident thereon, and wherein each diffractive element of the at least the first set is further configured to transmit a second fraction of the corresponding optical signal incident thereon; and
a second set of diffractive elements, wherein each diffractive element of the second set is configured to route, within the optical waveguide, the corresponding second fraction transmitted by each diffractive element of the at least the first set,
wherein each diffractive element of the at least the first set is further configured to impart a corresponding first transfer function onto the corresponding optical feedback signal to substantially restrict the corresponding optical signal to a corresponding wavelength range determined at least in part by the corresponding first transfer function.
40. The apparatus of claim 39 wherein the diffractive elements of the at least the first set are formed in a channel waveguide located in a first region of the optical waveguide, and wherein the diffractive elements of the second set are formed in a slab waveguide located in a second region of the optical waveguide.
41. The apparatus of claim 39, further comprising at least one optical source configured to provide the corresponding optical signal to the at least the first set of diffractive elements formed in or on the optical waveguide.
42. The apparatus of claim 39, further comprising a plurality of photodetectors each configured to receive the corresponding second fraction routed by the second set of diffractive elements.
43. The apparatus of claim 39 wherein each diffractive element of the second set is further configured to impart a corresponding second transfer function onto the corresponding second fraction.
44. An apparatus, comprising:
optical waveguide means for receiving an input optical signal;
at least a first set of diffractive element means for routing, as an optical feedback signal and within the optical waveguide means, a first fraction of the received input optical signal, for imparting a first transfer function onto the optical feedback signal to substantially restrict the input optical signal to a wavelength range determined at least in part by the first transfer function, and for transmitting a second fraction of the received optical input signal; and
a second set of diffractive element means for routing, within the optical waveguide means, the transmitted second fraction to an optical port.
45. The apparatus of claim 44 wherein the at least the first set of diffractive element means is formed in a channel waveguide located in a first region of the optical waveguide means, and wherein the second set of diffractive element means is formed in a slab waveguide located in a second region of the optical waveguide means.
46. The apparatus of claim 44, further comprising at least one optical source means for launching at least a corresponding portion of the input optical signal into the optical waveguide means.
47. The apparatus of claim 44, further comprising a plurality of detector means for receiving the second fraction transmitted to the optical port by the second set of diffractive element means.
48. A system, comprising:
a plurality of optical sources to respectively provide corresponding input optical signals; and
an optical waveguide that includes:
at least a first set of diffractive elements, wherein each diffractive element of the at least the first set is configured to route, as a corresponding optical feedback signal and within the optical waveguide, a first fraction of a corresponding input optical signal incident thereon, and wherein each diffractive element of the at least the first set is further configured to transmit a second fraction of the corresponding optical signal incident thereon; and
a second set of diffractive elements, wherein each diffractive element of the second set is configured to route, within the optical waveguide, the corresponding second fraction transmitted by each diffractive element of the at least the first set,
wherein each diffractive element of the at least the first set is further configured to impart a corresponding first transfer function onto the corresponding optical feedback signal to substantially restrict the corresponding optical signal to a corresponding wavelength range determined at least in part by the corresponding first transfer function, and
wherein each corresponding wavelength range substantially corresponds to an operating wavelength channel.
49. The system of claim 48 wherein each said operating wavelength channel is a channel of a wavelength division multiplexing (WDM) system.
50. The system of claim 48 wherein the plurality of optical sources includes a plurality of lasers.
51. The system of claim 49, further comprising a plurality of detectors each configured to receive the corresponding second fraction routed by the second set of diffractive elements.
Description
RELATED APPLICATIONS

This application is a continuation of U.S. non-provisional application Ser. No. 10/923,455 filed Aug. 21, 2004 (now U.S. Pat. No. 7,054,517), which in turn claims benefit of U.S. provisional App. No. 60/497,410 filed Aug. 21, 2003, each of said provisional and non-provisional applications being hereby incorporated by reference as if fully set forth herein.

U.S. application Ser. No. 10/923,455 is also a continuation-in-part of U.S. non-provisional application Ser. No. 10/653,876 filed Sep. 2, 2003 (now U.S. Pat. No. 6,829,417), which is in turn a continuation-in-part of U.S. non-provisional application Ser. No. 10/229,444 filed Aug. 27, 2002 (now U.S. Pat. No. 6,678,429), each of said non-provisional applications being hereby incorporated by reference as if fully set forth herein. U.S. application Ser. No. 10/229,444 in turn claims benefit of U.S. provisional App. No. 60/315,302 filed Aug. 27, 2001 and U.S. provisional App. No. 60/370,182 filed Apr. 4, 2002, each of said provisional applications being hereby incorporated by reference as if fully set forth herein.

U.S. application Ser. No. 10/923,455 is also a continuation-in-part of U.S. non-provisional application Ser. No. 09/811,081 filed Mar. 16, 2001 (now U.S. Pat. No. 6,879,441), and a continuation-in-part of U.S. non-provisional application Ser. No. 09/843,597 filed Apr. 26, 2001 (now U.S. Pat. No. 6,965,464), application Ser. No. 09/843,597 in turn being a continuation-in-part of said application Ser. No. 09/811,081. Said application Ser. No. 09/811,081 in turn claims benefit of: 1) U.S. provisional App. No. 60/190,126 filed Mar. 16, 2000; 2) U.S. provisional App. No. 60/199,790 filed Apr. 26, 2000; 3) U.S. provisional App. No. 60/235,330 filed Sep. 26, 2000; and 4) U.S. provisional App. No. 60/247,231 filed Nov. 10, 2000. Each of said provisional and non-provisional applications is hereby incorporated by reference as if fully set forth herein.

BACKGROUND

The field of the present invention relates to optical devices incorporating distributed optical structures. In particular, a multiple wavelength optical source incorporating at least one distributed optical structure is disclosed herein.

Distributed optical structures employed in the multiple wavelength optical sources disclosed or claims herein may be implemented with a variety of adaptations, such as those described in:

U.S. non-provisional application Ser. No. 09/811,081 entitled “Holographic spectral filter” filed Mar. 16, 2001 in the name of Thomas W. Mossberg (now U.S. Pat. No. 6,879,441);

U.S. non-provisional application Ser. No. 09/843,597 entitled “Optical processor” filed Apr. 26, 2001 (now U.S. Pat. No. 6,965,464);

U.S. non-provisional application Ser. No. 10/229,444 entitled “Amplitude and phase control in distributed optical structures” filed Aug. 27, 2002 in the names of Thomas W. Mossberg and Christoph M. Greiner (now U.S. Pat. No. 6,678,429);

U.S. non-provisional application Ser. No. 10/602,327 entitled “Holographic spectral filter” filed Jun. 23, 2003 in the name of Thomas W. Mossberg (now U.S. Pat. No. 6,859,318);

U.S. non-provisional application Ser. No. 10/653,876 entitled “Amplitude and phase control in distributed optical structures” filed Sep. 2, 2003 in the names of Thomas W. Mossberg and Christoph M. Greiner (now U.S. Pat. No. 6,829,417);

U.S. non-provisional application Ser. No. 10/740,194 entitled “Optical multiplexing device” filed Dec. 17, 2003 in the names of Dmitri Iazikov, Thomas W. Mossberg, and Christoph M. Greiner;

U.S. non-provisional application Ser. No. 10/794,634 entitled “Temperature-compensated planar waveguide optical apparatus” filed Mar. 5, 2004 in the names of Dmitri Iazikov, Thomas W. Mossberg, and Christoph M. Greiner (now U.S. Pat. No. 6,985,656);

U.S. non-provisional application Ser. No. 10/798,089 entitled “Optical structures distributed among multiple optical waveguides” filed Mar. 10, 2004 in the names of Christoph M. Greiner, Thomas W. Mossberg, and Dmitri Iazikov (now U.S. Pat. No. 6,823,115);

U.S. non-provisional application Ser. No. 10/842,790 entitled “Multimode planar waveguide spectral filter” filed May 11, 2004 in the names of Thomas W. Mossberg, Christoph M. Greiner, and Dmitri Iazikov (now U.S. Pat. No. 6,987,911);

U.S. non-provisional application Ser. No. 10/857,987 entitled “Optical waveform recognition and/or generation and optical switching” filed May 29, 2004 in the names of Lawrence D. Brice, Christoph M. Greiner, Thomas W. Mossberg, and Dmitri Iazikov (now U.S. Pat. No. 6,990,276); and

U.S. non-provisional application Ser. No. 10/898,527 entitled “Distributed optical structures with improved diffraction efficiency and/or improves optical coupling” filed Jul. 22, 2004 in the names of Dmitri Iazikov, Christoph M. Greiner, and Thomas W. Mossberg.

Each of these applications and patents is hereby incorporated by reference as if fully set forth herein.

SUMMARY

A method for forming an optical apparatus comprises: forming a planar optical waveguide; forming at least one set of locking diffractive elements in or on the planar optical waveguide; forming means for routing an optical signal corresponding to at least one said set of locking diffractive elements; and positioning a laser corresponding to at least one said set of locking diffractive elements. The planar optical waveguide substantially confines in at least one transverse spatial dimension optical signals propagating therein. Each laser is positioned so as to launch a corresponding laser optical signal into the planar optical waveguide so that the corresponding laser optical signal is successively incident on the diffractive elements of the corresponding locking diffractive element set. Each locking diffractive element set routes within the planar optical waveguide a fraction of the corresponding laser optical signal back to the corresponding laser, with a corresponding locking transfer function, as a corresponding locking optical feedback signal, thereby substantially restricting the corresponding laser optical signal to a corresponding laser operating wavelength range determined at least in part by the corresponding locking transfer function of the corresponding locking diffractive element set. Each corresponding routing means routes within the planar optical waveguide, between the corresponding laser and a corresponding output optical port with a corresponding routing transfer function, at least a portion of that fraction of the corresponding laser optical signal that is transmitted by the corresponding locking diffractive element set. The optical apparatus may comprise multiple lasers, multiple corresponding locking diffractive element sets, and multiple corresponding routing means, thereby comprising a multiple-wavelength optical source.

The locking diffractive element sets may be formed in corresponding channel waveguides formed in the planar optical waveguide, or may be formed in one or more slab waveguide regions of the planar optical waveguide. The multiple corresponding routing means may comprise corresponding routing diffractive element sets formed in a slab waveguide region of the planar optical waveguide, or may comprise an arrayed waveguide grating formed in the planar optical waveguide. The multiple lasers may be individually assembled with the planar waveguide, may be assembled with the planar waveguide as an integrated laser array, or may be integrated directly into the planar waveguide. The corresponding laser output signals may be routed to a single output port or to multiple output ports.

Objects and advantages pertaining to diffractive element sets, planar optical waveguides, or multiple-wavelength optical sources may become apparent upon referring to the disclosed embodiments as illustrated in the drawings or disclosed in the following written description or appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates schematically a planar waveguide with multiple locking diffractive element sets and multiple routing diffractive element sets, and multiple lasers.

FIG. 2 illustrates schematically a planar waveguide with multiple locking diffractive element sets and multiple routing diffractive element sets, and multiple lasers.

FIG. 3 illustrates schematically a planar waveguide with multiple locking diffractive element sets and multiple routing diffractive element sets, and multiple lasers.

FIGS. 4A-4D are schematic cross-sections of diffractive elements in a planar waveguide.

FIGS. 5A-5B are schematic top views of diffractive elements in a planar waveguide.

FIGS. 6A-6B illustrate schematically termination of a channel waveguide core in a planar waveguide.

FIG. 7 illustrates schematically a planar waveguide with multiple locking diffractive element sets and multiple routing diffractive element sets, multiple photodetectors, multiple variable optical attenuators, and multiple lasers.

FIG. 8 is a schematic cross-section of diffractive elements in a planar waveguide.

FIG. 9 illustrates schematically a planar waveguide with multiple locking diffractive element sets and multiple routing diffractive element sets, and multiple lasers.

FIG. 10 illustrates schematically a planar waveguide with multiple locking diffractive element sets and an arrayed-waveguide grating, and multiple lasers.

The embodiments shown in the Figures are exemplary, and should not be construed as limiting the scope of the present disclosure and/or appended claims.

DETAILED DESCRIPTION OF EMBODIMENTS

An optical apparatus according to the present disclosure comprises a planar optical waveguide having at least one set of diffractive elements. The planar optical waveguide substantially confines in at least one transverse dimension optical signals propagating therein, and is generally formed on or from a substantially planar substrate of some sort. The confined optical signals typically propagate as transverse optical modes supported or guided by the planar optical waveguide. These optical modes are particular solutions of the electromagnetic field equations in the space occupied by the waveguide. The planar optical waveguide may comprise a slab waveguide, substantially confining in one transverse dimension an optical signal propagating in two dimensions therein, or may comprise a channel waveguide, substantially confining in two transverse dimension an optical signal propagating therein. It should be noted that the term “planar waveguide” is not used consistently in the literature; for the purposes of the present disclosure and/or appended claims, the terms “planar optical waveguide” and “planar waveguide” are intended to encompass both slab and channel optical waveguides.

The planar waveguide typically comprises a core surrounded by lower-index cladding (often referred to as upper and lower cladding, or first and second cladding; these may or may not comprise the same materials). The core is fabricated using one or more dielectric, semiconductor, or other materials substantially transparent over a desired operating wavelength range. In some instances one or both claddings may be vacuum, air, or other ambient atmosphere. More typically, one or both claddings comprise material layers, with the cladding refractive indices n1 and n2 typically being smaller than the core refractive index ncore. (In some instances in which short optical paths are employed and some degree of optical loss can be tolerated, the cladding indices might be larger than the core index while still enabling the planar waveguide to support guided, albeit lossy, optical modes.) A planar waveguide may support one or more transverse modes, depending on the dimensions and refractive indices of the core and cladding. A wide range of material types may be employed for fabricating a planar waveguide, including but not limited to glasses, polymers, plastics, semiconductors, combinations thereof, or functional equivalents thereof. The planar waveguide may be secured to a substrate, for facilitating manufacture, for mechanical support, or for other reasons. A planar waveguide typically supports or guides one or more optical modes characterized by their respective amplitude variations along the confined dimension.

The set of diffractive elements of the planar optical waveguide may also be referred to as: a set of holographic elements; a volume hologram; a distributed reflective element, distributed reflector, or distributed Bragg reflector (DBR); a Bragg reflective grating (BRG); a holographic Bragg reflector (HBR); a directional photonic-bandgap structure; a mode-selective photonic crystal; or other equivalent terms of art. Each diffractive element of the set diffracts, reflects, scatters, or otherwise redirects a portion of an incident optical signal (said process hereinafter simply referred to as diffraction). Each diffractive element of the set typically comprises some suitable alteration of the planar waveguide (ridge, groove, index modulation, density modulation, and so on), and is spatially defined by a virtual one- or two-dimensional curvilinear diffractive element contour. The curvilinear shape of the contour may be configured to impart desired spatial characteristics onto the diffracted portion of the optical signal. The curvilinear contours may be smoothly curved, or may be approximated by multiple short, substantially linear contour segments (in some instances dictated by fabrication constraints). Implementation of a diffractive element with respect to its virtual contour may be achieved in a variety of ways, including those disclosed in the references cited hereinabove. Each curvilinear diffractive element is shaped to direct or route its diffracted portion of the optical signal between input and output optical ports. The relative spatial arrangement (e.g. longitudinal spacing) of the diffractive elements of the set, and the relative amplitude diffracted from each diffractive element of the set, yield desired spectral or temporal characteristics for the overall diffracted optical signal routed between the input and output optical ports. It should be noted that optical ports (input or output) may be defined structurally (for example, by an aperture, waveguide, fiber, lens, laser or other optical source, or other optical component) or functionally (i.e., by a spatial location, size, convergence, divergence, collimation, or propagation direction), or both structurally and functionally. In some instances a pair of corresponding input and output ports may comprise the same optical port (i.e., the diffracted portion of the optical signal is retro-reflected). In some instances the input and output ports may be interchanged (i.e., the action of the diffractive element set is symmetric). For a single-mode planar waveguide, such a set of diffractive elements may be arranged to yield an arbitrary spectral/temporal transfer function (i.e., diffracted amplitude and phase as functions of wavelength). In a multimode planar waveguide, modal dispersion or mode-to-mode coupling of diffracted portions of the optical signal may limit the range of spectral/temporal transfer functions that may be implemented.

The curvilinear diffractive elements of the set (or equivalently, their corresponding contours) are spatially arranged with respect to one another so that the corresponding portions of the optical signal diffracted by each element interfere with one another at the output optical port, so as to impart desired spectral or temporal characteristics onto the portion of the optical signal collectively diffracted from the set of diffractive elements and routed between the input and output optical ports. The diffractive elements in the set are arranged so that an input optical signal, entering the planar waveguide through an input optical port, is successively incident on diffractive elements of the set. For the purposes of the present disclosure or appended claims, “successively incident” shall denote a situation wherein a wavevector at a given point on the wavefront of an optical signal (i.e., a wavefront-normal vector) traces a path (i.e., a “ray path”) through the diffractive element set that successively intersects the virtual contours of diffractive elements of the set. Such wavevectors at different points on the wavefront may intersect a given diffractive element virtual contour at the same time or at differing times; in either case the optical signal is considered “successively incident” on the diffractive elements. A fraction of the incident amplitude is diffracted by a diffractive element and the remainder is transmitted and incident on another diffractive element, and so on successively through the set of diffractive elements. The diffractive elements may therefore be regarded as spaced substantially longitudinally along the propagation direction of the incident optical signal, and a given spatial portion of the wavefront of such a successively incident optical signal therefore interacts with many diffractive elements of the set. (In contrast, the diffractive elements of a thin diffraction grating, e.g. the grating lines of a surface grating, may be regarded as spaced substantially transversely across the wavefront of a normally incident optical signal, and a given spatial portion of the wavefront of such a signal therefore interacts with only one or at most a few adjacent diffractive elements).

The set of diffractive elements provides dual functionality, spatially routing an optical signal between an input optical port and an output optical port, while at the same time acting to impart a spectral/temporal transfer function onto the input optical signal to yield an output optical signal. The curvilinear diffractive elements may be designed (by computer generation, for example) so as to provide optimal routing, imaging, or focusing of the optical signal between an input optical port and a desired output optical port, thus reducing or minimizing insertion loss. Simple curvilinear diffractive elements (segments of circles, ellipses, parabolas, hyperbolas, and so forth), if not optimal, may be employed as approximations of fully optimized contours. Numerous short, substantially linear segments may be employed to approximate a smoothly curved contour. A wide range of fabrication techniques may be employed for forming the diffractive element set, and any suitable technique(s) may be employed while remaining within the scope of the present disclosure and/or appended claims. Particular attention is called to design and fabrication techniques disclosed in the references cited hereinabove. The following are exemplary only, and are not intended to be exhaustive.

Diffractive elements may be formed lithographically on the surface of a planar optical waveguide, or at one or both interfaces between core and cladding of a planar optical waveguide. Diffractive contours may be formed lithographically in the interior of the core layer or a cladding layer of the planar optical waveguide using one or more spatial lithography steps performed after an initial deposition of layer material. Diffractive elements may be formed in the core or cladding layers by projecting ultraviolet light or other suitable radiation through an amplitude or phase mask so as to create an interference pattern within the planar waveguide (fabricated at least in part with suitably sensitive material) whose fringe contours match the desired diffractive element contours. Alteration of the refractive index by exposure to ultraviolet or other radiation results in index-modulated diffractive elements. The mask may be zeroth-order-suppressed according to methods known in the art, including the arts associated with fabrication of fiber Bragg gratings. The amplitude or phase mask may be produced lithographically via laser writer or e-beam, it may be interferometrically formed, or it may be formed by any other suitable technique. In instances where resolution is insufficient to produce a mask having required feature sizes, a larger scale mask may be produced and reduced to needed dimensions via photoreduction lithography, as in a stepper, to produce a mask at the needed scale. Diffractive elements may be formed by molding, stamping, impressing, embossing, or other mechanical processes. A phase mask may be stamped onto the core or cladding surface followed by optical exposure to create diffractive elements throughout the core and or cladding region. The optical or UV source used to write the diffractive elements in this case should have a coherence length comparable or longer than the distance from the stamped phase mask to the bottom of the core region. Stamping of the phase mask directly on the device may simplify alignment of diffractive elements with ports or other device components, especially when those components may be formed in the same or another stamping process. Many approaches to the creation of refractive index modulations or gratings are known in the art and may be employed in the fabrication of diffractive element sets.

Irradiation-produced refractive index modulations or variations for forming diffractive elements will optimally fall in a range between about 10−4 and about 10−1; however, refractive index modulations or variations outside this range may be employed as well. Refractive index modulations or variations may be introduced by light of any wavelength (including ultraviolet light) that produces the desired refractive index changes, provided only that the photosensitive material employed is suitably stable in the presence of light in the desired operating wavelength range of the optical device. Exposure of a complete set of diffractive elements to substantially spatially uniform, refractive-index-changing light may be employed to tune the operative wavelength range of the diffractive element set. Exposure of the diffractive element set to spatially non-uniform refractive-index changing light may be employed to chirp or otherwise wavelength-modulate the diffractive element set (described further hereinbelow). The sensitivity of planar waveguide materials to irradiation produced refractive index modulations may be increased using hydrogen-loading, flame-brushing, boron or other chemical doping, or other method known in the art, for example in the context of making fiber Bragg gratings.

The curvilinear shape of the diffractive element contours may be determined by a variety of standard optical imaging system design tools. Essentially, each diffractive element contour may be optimized to image the input port onto the output port in a phase coherent manner. Inputs to the design are the detailed structure of the input and output optical ports and their locations. Standard ray tracing approaches to optical element design may provide a diffractive contour at each optical distance into the planar waveguide that will provide an optimal imaging of the input signal at the input port onto the optimal output signal at the output port. Simple curves may be employed as approximations of the fully optimized contours. Diffractive element virtual contours may be spaced by an optical path difference (as described above) that provides for the field image of successive diffractive contours to be substantially in phase at a desired wavelength. If the overall response of the diffractive element set is to be apodized with amplitude or phase modulation (to yield a desired spectral/temporal transfer function), the optical spacing of successive diffractive element contours may be varied in a controlled manner to provide required phase differences between diffracted components at the output port, or the diffractive strength of the elements may be individually controlled (as disclosed in the references cited hereinabove).

An alternative approach to designing the diffractive element contours for a diffractive element set is to calculate interference patterns between numerically simulated fields at a desired wavelength and with specified temporal waveforms entering the input port and exiting the output port. If a spectral transfer function is specified in a design, a corresponding temporal waveform may be obtained by Fourier transform. In forming or writing a summed pattern for the diffractive element set, suitable discretization is applied as needed for any lithographic or UV exposure approach that is utilized for fabrication. The holographic structure may be designed by interference of computer-generated beams having the desired computer-generated temporal waveforms, with the resulting calculated arrangement of diffractive elements implemented by lithography or other suitable spatially-selective fabrication techniques. For example, interference between a delta-function-like pulse and a desired reference optical waveform (or its time-reverse) may be calculated, and the resulting interference pattern used to fabricate a diffractive element set that acts to either recognize or generate the desired reference optical waveform.

In an alternative method for making the diffractive element structure, the core consists of a material of appropriate index that is also photosensitive at the wavelength of the desired operational signal beams. As in traditional holography, the input and output recording beams (same wavelength as operational signal beams of the envisioned device) are overlapped in the core and the interference pattern between them is recorded. Subsequently the core material is developed and, if necessary, a cladding may be deposited or attached by other means. A specified spectral transfer function may be generated by imparting spectrally sweeping the desired amplitude and phase variations on the recording beams, or the recording beams may be pulsed with temporal waveforms having the desired Fourier spectrum.

The phrase “operationally acceptable” appears herein describing levels of various performance parameters of planar waveguides and diffractive element sets thereof. Such parameters may include optical coupling coefficient (equivalently, optical coupling efficiency), diffraction efficiency, undesirable optical mode coupling, optical loss, and so on. An operationally acceptable level may be determined by any relevant set or subset of applicable constraints or requirements arising from the performance, fabrication, device yield, assembly, testing, availability, cost, supply, demand, or other factors surrounding the manufacture, deployment, or use of a particular assembled optical device. Such “operationally acceptable” levels of such parameters may therefor vary within a given class of devices depending on such constraints or requirements. For example, a lower optical coupling efficiency may be an acceptable trade-off for achieving lower device fabrication costs in some instances, while higher optical coupling may be required in other instances in spite of higher fabrication costs. In another example, higher optical loss (due to scattering, absorption, undesirable optical coupling, and so on) may be an acceptable trade-off for achieving lower device fabrication cost or smaller device size in some instances, while lower optical loss may be required in other instances in spite of higher fabrication costs and/or larger device size. Many other examples of such trade-offs may be imagined. Optical devices and fabrication methods therefor as disclosed herein, and equivalents thereof, may therefore be implemented within tolerances of varying precision depending on such “operationally acceptable” constraints or requirements. Phrases such as “substantially adiabatic”, “substantially spatial-mode-matched”, “so as to substantially avoid undesirable optical coupling”, and so on as used herein shall be construed in light of this notion of “operationally acceptable” performance.

Schematic plan views of exemplary embodiments of multiple-wavelength optical sources 1000 are shown in FIGS. 1-3. Multiple channel optical waveguide cores 1003 are formed in a region of planar waveguide 1001. Each channel waveguide core 1003 is positioned to receive a corresponding optical signal from a corresponding laser 1015. In FIG. 1, lasers 1015 comprise a set of individual lasers each independently assembled with the planar waveguide 1001. In FIG. 2, lasers 1015 comprise an integrated laser array that is assembled with the planar waveguide 1001. In FIG. 3, lasers 1015 are integrally formed on the planar waveguide 1001. Drive current or electronic control signals may be delivered to lasers 1015 via electrical conductors 1019. Each corresponding channel waveguide includes a set of locking diffractive elements 1011. Each laser optical signal launched along the corresponding channel waveguide core 1003 is successively incident on the diffractive elements of the corresponding locking diffractive element set 1011. The locking diffractive element sets 1011 each route along the corresponding channel waveguide core 1003 a fraction of the laser optical signal launched by the corresponding laser 1015 into the channel waveguide. The routed fraction of the optical signal is directed back to the laser to serve as a locking optical feedback signal. Each locking diffractive element set 1011 imparts onto the diffracted fraction of the optical signal a corresponding locking transfer function, which determines at least in part the operating wavelength range of the corresponding laser 1015. The spectral characteristics of the locking transfer function are independent of the operating current or other operating parameters of the laser, and the resulting optical feedback tends to substantially restrict the laser optical signal to a selected operating wavelength range in spite of variations in drive current or other laser operating parameters.

The lasers 1015 may typically comprise semiconductor devices, wherein injection of drive current results in optical gain. The laser optical signals may be modulated by modulation of the laser drive currents. The laser may include two reflectors (e.g. opposing facets of a semiconductor laser chip) and thereby form a resonant optical cavity for supporting laser oscillation. In this instance the combination of the laser 1015 with the locking diffractive element set 1011 in the channel waveguide results in an external-cavity feedback laser, wherein a portion of the laser output from the laser oscillator is re-injected back through the output facet to stabilize the laser within the wavelength range determined by the locking diffractive element set. In this instance, compensation (active or passive) may be required so that longitudinal modes of the laser resonant cavity and the external cavity substantially coincide; otherwise, the laser output power or laser wavelength may fluctuate to an unacceptable degree as the respective longitudinal mode frequencies drift relative to one another. Alternatively, reflectivity of the front laser facet may be suppressed (by a suitable anti-reflection coating, for example, thereby diminishing or suppressing laser oscillation supported only within the laser chip), and the locking diffractive element set may serve as a laser resonator mirror. In this instance the laser 1015 and the channel waveguide with locking diffractive element sets 1011 together comprise a hybrid resonant optical cavity for supporting laser oscillation within the wavelength range determined by the locking diffractive element set. Both of these scenarios shall fall within the scope of the present disclosure or appended claims.

The diffractive elements may be formed in the channel waveguides in any suitable way, including but not limited to those listed hereinabove, and including but not limited to those disclosed in the incorporated references listed hereinabove. Examples are shown in FIGS. 4A-4D, which are schematic side cross-sectional views of diffractive elements in a planar waveguide 11. The planar waveguide in these embodiments is formed on a substrate 9 and comprises a core 5 surrounded by cladding 1 and 3. Diffractive elements 8 may be formed within the core (FIG. 4A), in the cladding (FIG. 4B), on the cladding (FIG. 4C), at the interface between core and cladding (FIG. 4D), or any combination of these locations. The diffractive elements 8 may comprise core material (FIG. 4B; FIG. 4D, if the diffractive elements protrude into the cladding as shown), cladding material (FIGS. 4A and 4C; FIG. 4D, if the diffractive elements extend into the core), or one or more materials differing from the core material and the cladding material (FIGS. 4A-4D).

The locking transfer functions may be determined by the particular arrangement of the elements of the corresponding locking diffractive element sets in each channel waveguide. A particular transfer function is chosen to yield the desired spectral or temporal characteristics for the optical feedback signal directed back to the laser, typically to restrict the laser optical signal to an operating wavelength range, or to otherwise optimize performance of the feedback-locked laser. For example, such a feedback-locked laser may exhibit reduced wavelength fluctuations (within operationally acceptable limits) despite modulation of its drive current. The spectral locations λ1, λ2, λ3, . . . λN of these operating wavelength ranges may be chosen in any desired fashion. In one example, operating wavelength ranges may be selected to substantially correspond to operating wavelength channels of a wavelength-division-multiplexing (WDM) telecommunications system, such as the ITU telecommunications grid. If the set of operating wavelengths is spanned by the gain bandwidth of a single type of laser, then all of lasers 1015 may be substantially identical, with each operating wavelength determined by the corresponding locking diffractive element set.

To provide an optical feedback signal at a given vacuum wavelength λ, a periodic spacing between the diffractive elements of mλ/2nwg may be employed (where m is a non-negative integer diffractive order, and nwg is the effective index of the channel waveguide). An example is shown schematically in FIG. 5A, wherein substantially identical, substantially uniformly spaced diffractive elements 25 are provided along channel waveguide core 23. Desired spectral profiles of the locking transfer functions differing from that produced by a simple periodic diffractive element set may be achieved by manipulation of relative amplitude or phase (i.e. apodization) of portions of the optical signal diffracted by each element of the locking diffractive element sets, in turn achieved by proper relative arrangement of the diffractive elements in the planar waveguide. An example is shown in FIG. 5B, wherein the transverse extent of the diffractive elements 31 varies (introducing amplitude variation), and the spacing of the diffractive elements along channel waveguide core 29 varies as well (introducing phase variation, as at 30). This is described in hereinabove or disclosed in the references incorporated hereinabove. While the strongest diffraction of the optical signal occurs for a first-order set of diffractive elements (i.e. m=1), any diffractive order may be employed for providing the locking feedback optical signal. The overall reflectivity of the locking diffractive element sets may be selected to yield desired laser performance (within operationally acceptable limits), and may typically range between about 1% and about 50%. The appropriate choice of locking reflectivity depends on several variables, including laser drive current, laser power, laser cavity round-trip optical gain or loss, optical losses or spurious reflectivity between the laser and the channel waveguide, and so on.

The locking diffractive element sets may be positioned in the planar waveguide 1001 so that the optical round trip time between the back reflector of the laser and the distal end of the corresponding locking diffractive element set is less than the bit modulation period to be employed when using the lasers as data transmitters. For example, if the maximum desired data transmission rate is 2.5 Gbit/sec and the average effective index within the combined laser and channel waveguide cavity is about 1.5, then the total length (from back laser reflector to distal end of locking diffractive element set) should be less than about 4 cm, typically between a few millimeters and about 2 cm. The reflective bandwidth of the locking diffractive element set may be chosen to be on the order of the longitudinal mode spacing of the combined laser and channel waveguide cavity; smaller reflective bandwidth may result in unacceptably large laser power fluctuations as the cavity modes shift relative to the reflective bandwidth. The reflective bandwidth should be sufficiently wide to support a desired laser modulation rate or modulation bandwidth. Reflectivity of the interface between the lasers 1015 and the proximal ends of the channel waveguides may be chosen to yield desired laser performance. For example, it may be desirable to provide an anti-reflection coating (a single λ/4 layer, a λ/4 stack, or other) between the laser and the proximal end of the channel waveguide (on a laser facet, or on the proximal end face of the channel waveguide). Alternatively, it may be desirable to provide enhanced reflectivity between the laser and the channel waveguide. It may be desirable to manipulate the launch conditions between the lasers 1015 and the proximal ends of the corresponding channel waveguide cores 1003. For example, spatial mode matching may result in less optical loss, a greater fraction of the laser power being launched into the channel waveguide, and a higher level of locking feedback optical signal getting back to the laser. This may be achieved (within operationally acceptable limits) by suitable configuration, adaptation, or arrangement of the laser or the proximal end of the channel waveguide core 1003, or by additional optical components employed between the laser and channel waveguide, such as gradient or refractive lenses.

The fractions of the laser optical signals that are transmitted through the corresponding locking diffractive element sets constitute the outputs of the lasers. The transmitted fractions propagate along the corresponding channel waveguide cores 1003, exit the corresponding distal ends thereof, and enter a slab optical waveguide region 1002 of the planar waveguide 1001 (FIGS. 1-3). In this region the transmitted fractions of the laser optical signals each propagate in two dimensions and impinge on routing diffractive element sets 1027, which serve (along with distal portions of channel waveguide cores 1003, and channel waveguide core 1007) as means for routing the transmitted fractions of the laser optical signals between the corresponding laser and a corresponding output port. The transmitted fractions of the laser optical signals are successively incident on the diffractive elements of the routing diffractive element sets 1027. The multiple routing sets of diffractive elements are each arranged to route at least a portion of the transmitted fraction of the corresponding laser optical signal to a corresponding output optical port. In the exemplary embodiments of FIGS. 1-3, the distal ends of the channel waveguide cores 1003 function as the corresponding input ports of the corresponding diffractive element sets 1027. All of the routing diffractive element sets may route the corresponding optical signals to a single output port, or the routed optical signals may be routed among multiple output optical ports in any desired combination. An output optical port may comprise the end of a channel waveguide core 1007 formed on the planar waveguide 1001 (FIGS. 1 and 2), or may comprise a spatial beam size, beam shape, beam position, and beam propagation direction at an edge of the planar waveguide 1001 (designated 1008 in FIG. 3). The routed portions of the corresponding laser optical signals may enter an optical fiber 1023 positioned at the output port 1008 or at the end of channel waveguide core 1007, as the case may be. The output port(s) may be located on the same edge of the planar waveguide 1001 as the lasers 1015 (FIG. 1), may be located on an adjacent edge of planar waveguide 1001 (FIGS. 2 and 3), or may be located in any other suitable location on an edge of planar waveguide 1001. If multiple routed portions of the laser optical signals are routed to a common optical output port, then the corresponding routing diffractive element sets function as a multiplexer, and enable injection of multiple wavelength channels into a common optical fiber output.

The multiple routing diffractive element sets 1027 may comprise sets of curvilinear diffractive elements, with shapes chosen to route at least a portion of a diverging transmitted fraction of the corresponding laser optical signal to a corresponding output port, within operationally acceptable limits. The selection of suitable diffractive element shapes is described hereinabove or disclosed in the references incorporated hereinabove. The distal end of the channel waveguide cores 1003 may be tapered (FIG. 6A) or flared (FIG. 6B), as desired, to yield desired divergence of the laser optical signals in the slab waveguide region 1002. The end of a channel waveguide core 1007, if present, may be tapered or flared, as desired, to accommodate convergence of the routed laser optical signals in the slab waveguide region 1002. Within each routing diffractive element set, the diffractive elements may be arranged to yield substantially uniform phase shifts and substantially similar diffracted amplitudes, or may be arranged to yield various phase shifts and amplitudes to in turn yield a desired routing transfer function (i.e. desired apodization). The routing transfer function will typically overlap spectrally the corresponding locking transfer function imparted by the corresponding locking diffractive element set. The spacings or other arrangements of the routing diffractive elements are analogous to those already described for the locking diffractive element sets, and are described hereinabove or disclosed in the references incorporated hereinabove. The multiple routing diffractive element sets may be longitudinally displaced relative to one another (i.e. “stacked”) and therefore occupy separate areal portions of the slab waveguide region 1002 of the planar waveguide 1001. Or, the multiple routing diffractive element sets may occupy overlapping areal portions of the slab waveguide region 1002 of planar waveguide 1001. Such overlapping sets of diffractive elements may be overlaid or interleaved as disclosed in the references incorporated hereinabove.

It is typically intended that the fraction of the laser optical signal transmitted by the corresponding locking diffractive element set is diffracted only by the corresponding routing diffractive element set (and a portion thereof thereby routed to the corresponding output port). In this way multiple laser optical signals at multiple corresponding, differing wavelengths from multiple corresponding lasers may be routed to the corresponding output ports, or to a single output port, by diffraction from the corresponding routing diffractive element sets, even if the optical signals must propagate through other routing diffractive element sets.

An exemplary use of a multiple-wavelength optical source, such as the exemplary embodiments of FIGS. 1-3, may be transmission of multiple wavelength-differentiated data channels into a single output port or into a single output optical fiber. Another exemplary use is switching of a single data channel among multiple carrier wavelengths, by electronic switching of an electronic modulation signal among the various lasers of the multiple-wavelength source. These uses or other uses of the multiple-wavelength optical sources shall fall within the scope of the present disclosure or appended claims.

Since the locking diffractive element sets and the corresponding routing diffractive element sets are all formed on the same planar optical waveguide, it may be possible to form them in a single lithographic step or sequence. For example, all of the locking and routing diffractive elements may be defined on a common mask used to form the diffractive elements on the planar waveguide. The spectral characteristics of each locking diffractive element set and its corresponding routing diffractive element set, as well as the relative wavelength offsets of the various locking diffractive element sets (e.g. to match a corresponding wavelength channel spacing of a WDM system), may be very precisely set during the fabrication of such a mask. Once formed, any shifting of spectral characteristics of the various diffractive element sets due to environmental influences (such as temperature-induced wavelength shifts due to thermo-optic effects or thermal expansion of the planar waveguide) are well-correlated with one another, since all are formed on a common planar waveguide. If precise control of the absolute wavelengths is desired, a single temperature control mechanism may be employed for temperature stabilizing the planar waveguide, and all the diffractive element sets thereon. Such temperature control may be achieved by any suitable means, including any suitable temperature sensor, heat source, or feedback circuit, or other mechanism. The multiple-wavelength optical source may then be temperature-tuned to the desired wavelengths, or may be stabilized at a desired temperature or operating wavelengths.

In the exemplary embodiment of FIG. 7, each locking diffractive element set 1011 includes at least a section of higher-order diffractive elements 1051 (not visible in FIG. 7; shown in the schematic cross-section of FIG. 8), for redirecting a portion of the corresponding laser optical signal out of the planar waveguide. While the redirected portion of the optical signal represents optical loss during propagation along the channel waveguide, this redirected signal portion may be useful for monitoring the optical power level propagating along the channel waveguide. Photodetectors 1047 may be positioned above the higher-order section of diffractive elements 1051 for receiving the redirected portion of the optical signal. While any higher-order diffractive element set (i.e., higher than first order) will redirect a portion of the optical signal out of the planar waveguide, even-order diffractive element sets redirect at least one portion vertically from the planar waveguide, which may then be more efficiently collected by the photodetector. In the exemplary embodiment of FIG. 8, most of the locking diffractive element set 1011 is first-order (element spacing of λ/2nwg), and the higher-order section 1051 is second-order (element spacing of λ/nwg).

Photodetectors 1047 may be assembled individually onto the planar waveguide 1001 over the corresponding higher-order sections 1051 of the diffractive element sets 1011, or the photodetectors may comprise an integrated photodetector array assembled onto the planar waveguide 1001. Alternatively, photodetectors 1047 may be integrated directly into the planar waveguide 1001, above or below the higher-order section of diffractive elements. The signals generated by the photodetectors 1047 may be used to measure the optical signal power propagating through the channel waveguides for monitoring, diagnostics, trimming, signal normalization, feedback control, or for other purposes. For example, the planar waveguide may further comprise multiple corresponding variable optical attenuators 1043 for controlling the optical power level propagating through the segments of the corresponding channel waveguides distal to the attenuators. The attenuators 1043 may be operatively coupled to the corresponding photodetectors 1047 through a feedback circuit for maintaining the laser optical signal level reaching the corresponding routing diffractive element sets 1027 within a selected operating range. Alternatively, the signals generated by the photodetectors 1047 may be used as a feedback signal for controlling the laser drive current to the corresponding lasers 1015. These and any other suitable feedback mechanisms shall fall within the scope of the present disclosure or appended claims. Higher-order diffractive elements (for redirecting portions of the laser optical signals) or photodetectors may be positioned elsewhere besides the locking diffractive element sets. For example, the routing diffractive element sets may include higher-order sections, or other portions of channel waveguide cores 1003 or 1007 (instead of segments thereof having the locking diffractive element sets) may be provided with a higher-order set of diffractive elements for redirecting portions of the laser optical signals onto photodetectors. Any suitable location for positioning higher-order diffractive elements for redirecting portions of the laser optical signals to corresponding photodetectors shall fall within the scope of the present disclosure or appended claims.

In the exemplary embodiment illustrated schematically in FIG. 9, the locking diffractive element sets 1011 comprise curvilinear diffractive elements formed in the slab optical waveguide region 1002. The laser optical signals emerge from the distal ends of channel waveguide cores 1003, propagate in two dimensions through slab waveguide region 1002, and are successively incident on the locking diffractive elements of the corresponding sets 1011. The schematic cross-sectional views of FIGS. 4A-4D may represent curvilinear locking diffractive elements sets 1011. The curvilinear diffractive elements are shaped to redirect a fraction of the laser optical signal back to the laser with a locking transfer function, in a manner analogous to that described hereinabove for locking diffractive element sets formed in channel waveguides. Suitable curvilinear shapes may be determined in a manner analogous to those used for determining the curvilinear shapes of the routing diffractive element sets, as described hereinabove or disclosed in the references incorporated hereinabove. The fractions of the corresponding laser optical signals transmitted by the corresponding locking diffractive element sets are successively incident on the elements of the corresponding routing diffractive element sets 1027, which route portions of the corresponding laser optical signals to corresponding output port(s). The channel waveguide cores 1003 may be omitted completely, with the lasers 1015 launching the corresponding laser optical signals directly into slab waveguide region 1002. The curvilinear locking diffractive elements sets may include higher-order sections thereof, for directing a portion of the corresponding laser optical signals out of the planar waveguide, and corresponding photodetectors may be positioned for receiving these corresponding redirected portions. The curvilinear locking diffractive element sets may be stacked, overlaid, or interleaved in a manner analogous to that described hereinabove for the routing diffractive element set, or disclosed in the references incorporated hereinabove.

In the exemplary embodiment of FIG. 10, the routing means for routing the laser optical signals from the corresponding lasers 1015 to the corresponding output port (channel waveguide 1009 in this example) comprises an arrayed-waveguide grating 1029 formed on planar waveguide 1001 (along with distal portions of channel waveguide cores 1003, and channel waveguide core 1009). Locking diffractive element sets 1011 formed along corresponding channel waveguide cores 1003 provide corresponding locking feedback signals to the corresponding lasers 1015. The arrayed-waveguide grating (AWG; also referred to as a phased array or phased waveguide array) may be implemented in a variety of ways known in the art, so that the fractions of the corresponding laser optical signals transmitted by the corresponding locking diffractive element sets 1011 and propagating along corresponding channel waveguide cores 1003 are routed to corresponding output port(s). Various other aspects of the multiple-wavelength optical source may be modified as already described herein: lasers 1015 may comprise individual lasers assembled with the planar waveguide, an integrated array of lasers assembled with the planar waveguide, or lasers integrated into the planar waveguide; locking diffractive element sets 1011 may include corresponding higher-order sections for redirecting portions of the corresponding laser optical signals out of the planar waveguide 1001; other portions of channel waveguide cores 1003, waveguide core 1009, or the AWG 1029 may include corresponding higher-order sections for redirecting portions of the corresponding laser optical signals out of the planar waveguide 1001; corresponding photodetectors may receive redirected portions of the corresponding optical signals; photodetectors may comprise individual photodetectors assembled with the planar waveguide, an integrated array of photodetectors assembled with the planar waveguide, or photodetectors integrated into the planar waveguide; photodetector signals may provide feedback control of laser optical signal power; the multiple laser optical signals may be directed to one or more output optical ports; or laser optical signals directed to output ports may enter corresponding optical fibers.

A wide variety of materials may be employed for forming the planar waveguide and the locking diffractive element sets, channel waveguides, slab waveguide, routing diffractive element sets, arrayed-waveguide gratings, or other elements of a multiple-wavelength optical source, and any suitable material or combination of materials shall fall within the scope of the present disclosure or appended claims. A common material combination is a silicon substrate with silica cladding (doped or undoped as appropriate) and with doped silica or silicon nitride or silicon oxynitride waveguide cores. If lasers or photodetectors are to be integrated into the planar waveguide, suitable materials must be chosen for the planar waveguide that are compatible with laser or photodetector materials at the operating wavelengths of the device. For typical telecommunications wavelengths, these will typically include III-V semiconductors or various alloys thereof.

Whether integrated into the planar waveguide, or assembled with the planar waveguide as an integrated array, lasers or photodetectors are subject to yield limitations in their manufacture. So that a single sub-standard laser or photodetector does not result in rejection of an entire array, arrays may be constructed with extra lasers or photodetectors. The planar waveguide may be fabricated with extra locking diffractive element sets and extra routing means to accommodate these extra lasers or photodetectors. In this way, if a laser or photodetector of an array is bad, the array may still be used. The corresponding electronic channels are simply switched on or off accordingly, to only use channels having a good laser or a good photodetector.

In the present disclosure or appended claims, the conjunction “or” is to be construed inclusively (e.g., “a dog or a cat” would be interpreted as “a dog, or a cat, or both”; Bryan A. Garner, Elements of Legal Style p. 103, 2nd ed. 2002), unless: i) it is explicitly stated otherwise, e.g., by use of “either-or”, “only one of”, or similar language; or ii) two or more of the listed alternatives are mutually exclusive within the specific context, in which case “or” would encompass only those combinations involving non-mutually-exclusive alternatives, if any.

It should be noted that many of the embodiments depicted in this disclosure are only shown schematically, and that not all the features may be shown in full detail or in proper proportion or location. Certain features or structures may be exaggerated relative to others for clarity. In particular, it should be noted that the numbers of diffractive elements in an actual device may typically be larger than that shown in the Figures. The numbers of diffractive elements is reduced in the Figures for clarity. It should be further noted that the embodiments shown in the Figures are exemplary only, and should not be construed as specifically limiting the scope of the written description or the claims set forth herein. It is intended that equivalents of the disclosed exemplary embodiments or methods shall fall within the scope of the present disclosure. It is intended that the disclosed exemplary embodiments or methods, or equivalents thereof, may be modified while remaining within the scope of the present disclosure or appended claims.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3995937Sep 3, 1975Dec 7, 1976Siemens AktiengesellschaftTunable optical wave guide systems
US4006967Apr 23, 1975Feb 8, 1977Battelle Memorial InstituteDirecting optical beam
US4140362Jul 14, 1977Feb 20, 1979Bell Telephone Laboratories, IncorporatedForming focusing diffraction gratings for integrated optics
US4387955Feb 3, 1981Jun 14, 1983The United States Of America As Represented By The Secretary Of The Air ForceHolographic reflective grating multiplexer/demultiplexer
US4440468Aug 25, 1981Apr 3, 1984Siemens AktiengesellschaftPlanar waveguide bragg lens and its utilization
US4660934Mar 12, 1985Apr 28, 1987Kokusai Denshin Denwa Kabushiki KaishaMethod for manufacturing diffraction grating
US4740951Mar 13, 1986Apr 26, 1988Commissariat A L'energie AtomiqueReversible device for the demultiplexing of several light signals in integrated optics
US4743083Dec 30, 1985May 10, 1988Schimpe Robert MCylindrical diffraction grating couplers and distributed feedback resonators for guided wave devices
US4746186Aug 31, 1987May 24, 1988U.S. Philips Corp.Reflection grating
US4773063Nov 13, 1984Sep 20, 1988University Of DelawareOptical wavelength division multiplexing/demultiplexing system
US4786133Dec 18, 1987Nov 22, 1988Commissariat A L'energie AtomiqueMultiplexer-demultiplexer using an elliptical concave grating and produced in integrated optics
US4803696Jun 30, 1987Feb 7, 1989Hughes Aircraft CompanyLaser with grating feedback unstable resonator
US4824193Jul 25, 1986Apr 25, 1989Matsushita Electric Industrial Co., Ltd.Holographic multiplexer/demultiplexer and its manufacturing method
US4834474May 1, 1987May 30, 1989The University Of RochesterOptical systems using volume holographic elements to provide arbitrary space-time characteristics, including frequency-and/or spatially-dependent delay lines, chirped pulse compressors, pulse hirpers, pulse shapers, and laser resonators
US4846552Feb 9, 1988Jul 11, 1989The United States Of America As Represented By The Secretary Of The Air ForceMethod of fabricating high efficiency binary planar optical elements
US4852960Sep 23, 1988Aug 1, 1989American Telephone And Telegraph Company, At&T Bell LaboratoriesNarrow-linewidth resonant optical device, transmitter, system, and method
US4923271Mar 28, 1989May 8, 1990American Telephone And Telegraph CompanyOptical multiplexer/demultiplexer using focusing Bragg reflectors
US4938553Mar 15, 1988Jul 3, 1990Siemens AktiengesellschaftArrangement for an integrated optical spectrometer and the method for manufacturing the spectrometer
US5040864Nov 13, 1990Aug 20, 1991Rockwell International CorporationOptical crosspoint switch module
US5042898Dec 26, 1989Aug 27, 1991United Technologies CorporationIncorporated Bragg filter temperature compensated optical waveguide device
US5093874Apr 1, 1991Mar 3, 1992Eastman Kodak CompanyIntegrated electro-optical scanner with photoconductive substrate
US5107359Nov 22, 1989Apr 21, 1992Ricoh Company, Ltd.Optical wavelength-divison multi/demultiplexer
US5165104Mar 1, 1991Nov 17, 1992Optivideo CorporationOptical interconnecting device and method
US5195161Dec 11, 1991Mar 16, 1993At&T Bell LaboratoriesA silicon layer and silicon dioxide cladding layer
US5274657Jun 4, 1992Dec 28, 1993Matsushita Electric Industrial Co., Ltd.Phase lock type semiconductor laser
US5357591Apr 6, 1993Oct 18, 1994Yuan JiangCylindrical-wave controlling, generating and guiding devices
US5450511Jul 25, 1994Sep 12, 1995At&T Corp.Efficient reflective multiplexer arrangement
US5453871Jun 14, 1989Sep 26, 1995Hewlett-Packard CompanyTemporal imaging with a time lens
US5668900Nov 1, 1995Sep 16, 1997Northern Telecom LimitedTaper shapes for sidelobe suppression and bandwidth minimization in distributed feedback optical reflection filters
US5768450Jan 11, 1996Jun 16, 1998Corning IncorporatedWavelength multiplexer/demultiplexer with varied propagation constant
US5812318Jul 21, 1997Sep 22, 1998University Of WashingtonApparatus and methods for routing of optical beams via time-domain spatial-spectral filtering
US5830622Feb 14, 1995Nov 3, 1998The University Of SydneyProduction of narrow band transmission antireflection filters
US5887094Aug 29, 1997Mar 23, 1999Alcatel Alsthom Compagnie Generale D'electriciteBand-pass filter in an optical waveguide
US5907647Feb 18, 1997May 25, 1999Lucent Technologies Inc.Long-period grating switches and devices using them
US5995691May 1, 1998Nov 30, 1999Hitachi Cable, Ltd.Waveguide type grating device
US6011884Dec 13, 1997Jan 4, 2000Lightchip, Inc.Integrated bi-directional axial gradient refractive index/diffraction grating wavelength division multiplexer
US6011885Dec 13, 1997Jan 4, 2000Lightchip, Inc.Integrated bi-directional gradient refractive index wavelength division multiplexer
US6021242Jul 23, 1998Feb 1, 2000Sumitomo Electric IndustriesDiffraction grating type band-pass filter and method of making the same
US6137933Feb 25, 1999Oct 24, 2000Lightchip, Inc.Integrated bi-directional dual axial gradient refractive index/diffraction grating wavelength division multiplexer
US6144480Feb 27, 1997Nov 7, 2000Li; MingOptical arrangement for processing an optical wave
US6169613Jun 3, 1997Jan 2, 2001Yeda Research & Devel Co., Ltd.Planar holographic optical device for beam expansion and display
US6169614May 21, 1999Jan 2, 2001Psc Scanning, Inc.Wedged-shape holographic collector
US6243514Apr 30, 1998Jun 5, 2001Nortel Networks LimitedOptical multiplexer/demultiplexer
US6266463Jun 18, 1998Jul 24, 2001Pirelli Cavi E Sistemi S.P.A.Chirped optical fibre grating
US6285813Oct 2, 1998Sep 4, 2001Georgia Tech Research CorporationDiffractive grating coupler and method
US6323970Sep 26, 2000Nov 27, 2001Digilents, Inc.Method of producing switchable holograms
US6408118Aug 25, 2000Jun 18, 2002Agere Systems Guardian Corp.Optical waveguide gratings having roughened cladding for reduced short wavelength cladding mode loss
US6473232Mar 6, 2001Oct 29, 2002Canon Kabushiki KaishaOptical system having a diffractive optical element, and optical apparatus
US6553162Nov 15, 2000Apr 22, 2003Oki Electric Industry Co., Ltd.Optical multiplexer-demultiplexer with mutually intersecting sub-gratings
US6603901Mar 3, 2000Aug 5, 2003Lucent Technologies Inc.Optical fiber Bragg grating comprises a length of gloss optical fiber having a core, a Bragg grating formed along the core, a glass cladding and a polymer coating on the cladding having an index of refraction matched to that the cladding.
US6678429Aug 27, 2002Jan 13, 2004Lightsmyth Technologies, Inc.Amplitude and phase control in distributed optical structures
US6702897Oct 9, 2001Mar 9, 2004Acme Grating Ventures, LlcOptical transmission systems and apparatuses including bragg gratings and methods of making
US6718093Oct 28, 2002Apr 6, 2004Advanced Interfaces, LlcIntegrated optical multiplexer and demultiplexer for wavelength division transmission of information
US6768834Jun 13, 2003Jul 27, 2004Agilent Technologies, Inc.Slab optical multiplexer
US6781944Feb 9, 2000Aug 24, 2004Hitachi, Ltd.Optical information processor with monolithically integrated light emitting device, light receiving devices and optics
US6813048Dec 17, 2002Nov 2, 2004Dai Nippon Printing Co., Ltd.Computer-generated hologram fabrication process, and hologram-recorded medium
US6823115Mar 10, 2004Nov 23, 2004Christoph M. GreinerOptical structures distributed among multiple optical waveguides
US6829417Sep 2, 2003Dec 7, 2004Christoph M. GreinerAmplitude and phase control in distributed optical structures
US6836492Jan 28, 2003Dec 28, 2004Hitachi, Ltd.Laser-diode module, optical transceiver and fiber transmission system
US6850670Jun 28, 2001Feb 1, 2005Lightwave Microsytstems CorporationMethod and apparatus for controlling waveguide birefringence by selection of a waveguide core width for a top clad
US6859318Jun 23, 2003Feb 22, 2005Thomas W. MossbergMethod for forming a holographic spectral filter
US6876791Jun 28, 2002Apr 5, 2005Sumitomo Electric Industries, Ltd.Diffraction grating device
US6879441Mar 16, 2001Apr 12, 2005Thomas MossbergHolographic spectral filter
US6928223Jul 11, 2001Aug 9, 2005Massachusetts Institute Of TechnologyStab-coupled optical waveguide laser and amplifier
US6961491Nov 15, 2004Nov 1, 2005Lightsmyth Technologies IncOptical structures distributed among multiple optical waveguides
US6965464Apr 26, 2001Nov 15, 2005Lightsmyth Technologies IncOptical processor
US6965716Nov 15, 2004Nov 15, 2005Lightsmyth Technologies IncAmplitude and phase control in distributed optical structures
US6985656Mar 5, 2004Jan 10, 2006Lightsmyth Technologies IncTemperature-compensated planar waveguide optical apparatus
US6987911May 11, 2004Jan 17, 2006Lightsmyth Technologies, Inc.Multimode planar waveguide spectral filter
US6990276May 29, 2004Jan 24, 2006Lightsmyth Technologies, Inc.Optical waveform recognition and/or generation and optical switching
US6993223Nov 26, 2004Jan 31, 2006Lightsmyth Technologies, Inc.Multiple distributed optical structures in a single optical element
US7003187Jul 13, 2001Feb 21, 2006Rosemount Inc.Optical switch with moveable holographic optical element
US7009743Sep 28, 2005Mar 7, 2006Lightsmyth Technologies IncOptical processor
US7016569Jul 30, 2003Mar 21, 2006Georgia Tech Research CorporationBack-side-of-die, through-wafer guided-wave optical clock distribution networks, method of fabrication thereof, and uses thereof
US7049704May 6, 2004May 23, 2006Intel CorporationFlip-chip package integrating optical and electrical devices and coupling to a waveguide on a board
US7054517Aug 21, 2004May 30, 2006Lightsmyth Technologies IncMultiple-wavelength optical source
US7062128Mar 8, 2005Jun 13, 2006Lightsmyth Technologies IncHolographic spectral filter
US7116453Feb 23, 2006Oct 3, 2006Lightsmyth Technologies Inc.Optical processor
US7116852Dec 11, 2001Oct 3, 2006Keio UniversityOptical signal processing circuit and method of producing same
US7120334Aug 25, 2005Oct 10, 2006Lightsmyth Technologies IncOptical resonator formed in a planar optical waveguide with distributed optical structures
US7123794Feb 9, 2005Oct 17, 2006Lightsmyth Technologies IncDistributed optical structures designed by computed interference between simulated optical signals
US7181103Feb 17, 2005Feb 20, 2007Lightsmyth Technologies IncOptical interconnect structures incorporating sets of diffractive elements
US7190859Sep 17, 2006Mar 13, 2007Lightsmyth Technologies IncDistributed optical structures in a planar waveguide coupling in-plane and out-of-plane optical signals
US7194161Jun 30, 2000Mar 20, 2007The Regents Of The University Of CaliforniaWavelength-conserving grating router for intermediate wavelength density
US7209611May 13, 2004Apr 24, 2007Infinera CorporationTransmitter photonic integrated circuit (TxPIC) chips utilizing compact wavelength selective combiners/decombiners
US7224855Dec 17, 2003May 29, 2007Lightsmyth Technologies Inc.Optical multiplexing device
US7260290Dec 23, 2004Aug 21, 2007Lightsmyth Technologies IncDistributed optical structures exhibiting reduced optical loss
US7286732Mar 13, 2007Oct 23, 2007Lightsmyth Technologies Inc.Distributed optical structures designed by computed interference between simulated optical signals
US7499612Jan 17, 2006Mar 3, 2009Mossberg Thomas WMultimode planar waveguide spectral filter
US20020071646Dec 8, 2000Jun 13, 2002Eggleton Benjamin JohnWaveguide incorporating tunable scattering material
US20030011833Apr 26, 2001Jan 16, 2003Vladimir YankovPlanar holographic multiplexer/demultiplexer
US20030039444Aug 27, 2002Feb 27, 2003Mossberg Thomas W.Amplitude and phase control in distributed optical structures
US20030068113Jan 25, 2002Apr 10, 2003Siegfried JanzMethod for polarization birefringence compensation in a waveguide demultiplexer using a compensator with a high refractive index capping layer.
US20030117677Apr 26, 2001Jun 26, 2003Mossberg Thomas W.Optical processor
US20030185269Mar 13, 2003Oct 2, 2003Gutin Mikhail A.Fiber-coupled vertical-cavity surface emitting laser
US20040047561Dec 11, 2001Mar 11, 2004Hiroyuki TudaOptical signal processing circuit and method of producing same
US20040076374Sep 2, 2003Apr 22, 2004Greiner Christoph M.Amplitude and phase control in distributed optical structures
US20040131360Dec 17, 2003Jul 8, 2004Dmitri IazikovOptical multiplexing device
US20040170356Mar 5, 2004Sep 2, 2004Dmitri IazikovTemperature-compensated planar waveguide optical apparatus
Non-Patent Citations
Reference
1Alavie et al., "A Multiplexed Bragg Grating Fiber Laser Sensor System", IEEE Photonics Tech. Lett., vol. 5 No. 9 pp. 1112-1114 (Sep. 1993).
2Avrutsky et al., "Multiwavelength Diffraction and Apodization Using Binary Superimposed Gratings", IEEE Photonics Tech. Lett., vol. 10 No. 6 pp. 839-841 (Jun. 1998).
3Babbitt et al, "Spatial Routing of Optical Beams Through Time-Domain Spatial-Spectral Filtering", Opt. Lett., vol. 20 No. 8 pp. 910-912 (Apr. 1995).
4Babbitt et al., "Optical Waveform Processing Routing with Structured Surface Gratings", Opt. Commun., vol. 148 pp. 23-26 (1998).
5Backlund et al, Multifunctional grating couplers for bidirectional incoupling into planar waveguides., IEEE Photonics Tech. Lett., vol. 12 No. 3 pp. 315-316 (Mar. 2000).
6Bai, et al., "Real-Time Optical Waveform Convolver/Cross Correlator", Applied Physics Letters vol. 45 No. 7, pp. 714-716 (1984).
7Bates et al, Gaussian beams from variable groove depth grating couplers in planar waveguides, Appl. Opt., vol. 32 No. 12 pp. 2112-2116 (Apr. 1993).
8Bedford et al, Bow-Tie Surface-Emitting Lasers, IEEE Photonics Technology Letters, vol. 12 No. 8 p. 948 (Aug. 2000).
9Brady et al, Holographic Interconnections in Photorefractive Waveguides., Applied Optics, vol. 30 No. 17 p. 2324 (Jun. 1991).
10Brazas et al, Analysis of input-grating couplers having finite lengths., Appl. Opt., vol. 34 No. 19 pp. 3786-3792 (Jul. 1995).
11Brigham et al, Analysis of scattering from large planar gratings of compliant cylindrical shells, J. Acoust. Soc. A., vol. 61 No. 1 pp. 48-59 (Jan. 1977).
12Canning et al, Grating structures with phase mask period in silica-on-silicon planar waveguides., Opt. Commun., vol. 171 pp. 213-217 (1999).
13Capmany, et al., "Autocorrelation Pulse Distortion in Optical Fiber CDMA Systems Employing Ladder Networks", Journal of Lighwave Technology vol. 17 No. 4, p. 570, 1999.
14Capron et al, Design and Performance of a Multiple Element Slab Waveguide Spectrograph for Multimode Fiber-Optic WDM System., J. Lightwave Tech., vol. 11 No. 12 pp. 2009-2014 (Dec. 1993).
15Chang, et al., "Fiber-Optic Ladder Networks for Inverse Decoding Coherent CDMA", Journal of Lighwave Technology vol. 10 No. 12, pp. 1952-1962, Dec. 1992.
16Chen et al, Guided-wave planar optical interconnects using highly multiplexed polymer waveguide holograms., J. Lightwave Tech., vol. 10 No. 7 pp. 888-897 (Jul. 1992).
17Chen et al, Ten channel single-mode wavelength division demultiplexer in the near IR, Integrated Optical Circuits, vol. 1583 pp. 134-142 (Intl. Soc. Opt. Eng., Boston, MA, USA, Sep. 1991).
18Chen, et al., "Applications of Ultrashort Pulse Propagation in Bragg Gratings for Wavelength-Division Multiplexing and Code-Division Multiple Access", IEEE Journal of Quantum Electronics vol. 34 No. 11, pp. 2117-2129, Nov. 1998.
19Chen, et al., "Wavelength-Encoding/Temporal-Spreading Optical Code Division Multiple-Access System with In-Fiber Moiré Gratings", Applied Optics vol. 38 No. 21, pp. 4500-4508 (1999).
20Cornwell, et al., "Experimental Demonstration of Coherent Coding of Picosecond Pulses", Electronics Letters vol. 34 No. 2, pp. 204-2-5, 1998.
21Cowin et al., Compact polymeric wavelength division multiplexer., Electron. Lett., vol. 35 No. 13 pp. 1074-1076 (Jun. 1999).
22Day et al, Filter-Response Line Shapes of Resonant Waveguide Grating., J. Lighwave Tech., vol. 14 No. 8 pp. 1815-1824 (Aug. 1998).
23Deri et al, Quantitative Analysis of Integrated Optic Waveguide Spectromenters, IEEE Photonics Tech. Lett. vol. 6 No. 2 pp. 242-244 (Feb. 1994).
24Eldada et al, Dispersive properties of planar polymer bragg gratings., IEEE Photonics Tech. Lett., vol. 12 No. 7 pp. 819-821 (Jul. 2000).
25Eriksson et al, Parabolic-Confocal Unstable-Resonator Semiconductor Lasers-Modeling and Experiments, IEEE J. Quantum Electronics, vol. 34 No. 5 p. 858 (May 1998).
26Eriksson et al, Surface-Emitting Unstable-Resonator Lasers with Integrated Diffractive Beam-Forming Elements, IEEE Photonics Technology Letters, vol. 9 No. 12 p. 1570 (Dec. 1997).
27Fathallah, et al., "Passive Optical Fast Frequency-Hop CDMA Communication System", Journal of Lighwave Technology, vol. 17 No. 3, pp. 397-405, Mar. 1999.
28Fu et al, 1×8 supergrating wavelength-division demultiplexer in a silica planar waveguide., Opt. Lett., vol. 22 No. 21 pp. 1627-1629 (1997).
29Gini et al, Polarization Independent InP WDM Multiplexer/Demultiplexer Module, J. Lighwave Tech., vol. 16 No. 4 pp. 625-630 (Apr. 1998).
30Grunnet-Jepsen et al, Fibre Bragg grating based spectral encoder/decoder for lightwave CDMA, Electon. Lett., vol. 35 No. 13 pp. 1096-1097 (Jun. 1999).
31Grunnett-Jepsen et al, Demonstration of All-Fiber Sparse Lighwave CDMA Based on Temporal Phase Encoding, Photonics Tech. Lett., vol. 11 No. 10 p. 1283 (Oct. 1999).
32Henry, Four-Channel Wavelength Division Multiplexers and Bandpass Filters Based on Elliptical Bragg Reflectors,. J. Lighwave Tech., vol. 8 No. 5 99 748-755 (May 1990).
33Hirayama et al., "Novel Surface Emitting Laser Diode Using Photonic Band-Gap Cavity," Appl. Phys. Lett 69(6), Aug. 5, 1996.
34International Preliminary Examination Report, mailed Feb. 23, 2004 for application PCT/US02/27288.
35International Preliminary Examination Report, mailed Jul. 26, 2004 for application PCT/US02/08199.
36International Preliminary Examination Report, mailed Oct. 6, 2006 for application PCT/US02/12869.
37International Search Report, mailed Aug. 22, 2002 for application PCT/US02/08199.
38International Search Report, mailed Feb. 26, 2003 for application PCT/US02/12869.
39International Search Report, mailed Jan. 2, 2003 for application PCT/US02/27288.
40International Search Report, mailed May 5, 2004 for application PCT/US03/27472.
41Japanese Office Action mailed Mar. 18, 2010 for application 2003-524057.
42JP Office Action, mailed Aug. 15, 2008 for application 2003-524057.
43Kaneko et al, Design and Applications for silica-based planar lightwave circuits., IEEE J. Sel. Top. Quant. Elec., vol. 5 No. 5 pp. 1227-1236 (Sep./Oct. 1999).
44Kato, et al., "PLC Hybrid Integration Technology and Its Application to Photonics Components", vol. 6 No. 1, pp. 4-13, Jan./Feb. 2000.
45Kazarinov et al, Narrow-Band Resonant Optical Reflectors and Resonant Optical Transformers for Laser Stablization and Wavelength Division Multiplexing, IEEE J. Quantum Electronics, vol. QE-23 No. 9 p. 1419 (Sep. 1987).
46Koontz et al, Preservation of rectangular-patterned InP gratings overgrown by gas source molecular beam epitaxy., Appl. Phys. Lett., vol. 71 No. 10 pp. 1400-1402 (Sep. 1997).
47Kristjansson et al, Surface-Emitting Tapered Unstable Resonator Laser with Integrated Focusing Grating Coupler, IEEE Photonics Technology Letters, vol. 12 No. 10 p. 1319 (Oct. 2000).
48Kurokawa et al, Time-space-conversion optical signal processing using arrayed-waveguide grating., Electron. Lett., vol. 33 No. 22 pp. 1890-1891 (Oct. 1997).
49Li, Analysis of planar waveguide grating couplers with double surface corrugations of identical periods., Opt. Commun., vol. 114 pp. 406-412 (1995).
50Lohmann, et al., "Graphic Codes for Computer Holography," Applied Optics, vol. 34, No. 17, Jun. 10, 1995.
51Madsen et al, Planar Waveguide Optical Spectrum Analyzer Using a UV-Induced Grating, IEEE J. Sel. Yop. Quant. Elec., vol. 4 No. 6 pp. 925-929 (Nov./Dec. 1998).
52Magnusson et al, New Principle for optical filters., Appl. Phys. Lett., vol. 61 No. 9 pp. 1022-1024 (Aug. 1992).
53Marhic, "Coherent Optical CDMA Networks", Journal of Lighwave Technology vol. 11 No. 5, pp. 854-864, 1993.
54Mazurenko, Y.T., "Holography of Wave Packets", Applied Physics B 50 pp. 101-114 (1990).
55Mazurenko, Y.T., "Time-Domain Fourier Transform Holography and Possible Applications in Signal Processing", Optical Engineering vol. 31 No. 4 pp. 739-749 Apr. 1992.
56Mazurenko, Yu T., "Reconstruction of a Time-Varying Wavegront by Multibeam Interference", Sov. Tech. Phys. Lett. 10, 228 (1984).
57McGreer, Diffraction from Concave Gratings in Planar Waveguides, IEEE Photonics Tech. Lett., vol. 7 No. 3 pp. 324-326 (Mar. 1995).
58McGreer, Tunable Planar Concave Grating Demultiplexer, IEEE Photonics Tech. Lett., vol. 8 No. 4 pp. 551-553 (Apr. 1996).
59Merkel, et al., "Optical Coherent Transient True-Time Delay Regenerator", Optics Letters vol. 21 No. 15, pp. 1102-1104, Aug. 1, 1996.
60Minier et al, Diffraction characteristics of superimposed holographic gratings in planar optical waveguides, IEEE Photonics Tech. Lett., vol. 4 No. 10 p. 115 (Oct. 1992).
61Miya, Silica-based planar lightwave circuits: passive thermally active devices., IEEE J. Sel. Top. Quant. Elec., vol. 6 No. 1 pp. 38-45 (Jan./Feb. 2000).
62Modh et al, "Deep-Etched Distributed Bragg Reflector Lasers with Curved Mirrors-Experiments and Modeling" IEEE J. Quantum Electronics, vol. 37 No. 6 p. 752 (Jun. 2001).
63Mossberg, "Planar Holographic Optical Processing Devices", Optics Letters, USA, Optical Society of America, vol. 26, No. 7, pp. 414-416 (Apr. 1, 2001).
64Mossberg, "Time-Domain Frequency-Selective Optical Data Storage", Optics Letters vol. 7 No. 2, pp. 77-79, 1982.
65Mossberg, et al., "Lithographic Holography in Planar Waveguides", SPIE International Technical Group Newsletter vol. 12 No. 2 Nov. 2001.
66Notice of Allowability mailed Jun. 25, 2009 for U.S. Appl. No. 11/280,876.
67Notice of Allowance mailed Feb. 10, 2010 for U.S. Appl. No. 12/367,159.
68Notice of Allowance mailed Feb. 5, 2010 for U.S. Appl. No. 11/676,273.
69Notice of Allowance mailed Jan. 28, 2010 for U.S. Appl. No. 11/280,876.
70Notice of Allowance mailed Jan. 8, 2010 for U.S Appl. No. 11/676,273.
71Notice of Allowance mailed Mar. 2, 2010 for U.S. Appl. No. 12/403,281.
72Notice of Allowance mailed Oct. 30, 2009 for U.S. Appl. No. 12/403,281.
73Office Action mailed Dec. 10, 2009 for U.S Appl. No. 12/408,039.
74Office Action mailed Jul. 1, 2008 for U.S. Appl. No. 11/280,876.
75Office Action mailed Mar. 5, 2009 for U.S. Appl. No. 11/280,876.
76Office Action mailed Oct. 9, 2007 for U.S. Appl. No. 11/280,876.
77Office Action, issued in EP Patent Application No. 02 796 438.6, mailed Apr. 27, 2010.
78Office Action, issued in U.S. Appl. No. 12/408,039, mailed May 7, 2010.
79Office Action, mailed Apr. 2, 2003 for U.S. Appl. No. 09/811,081.
80Office Action, mailed Apr. 7, 2009 for U.S. Appl. No. 11/676,273.
81Office Action, mailed Aug. 11, 2006 for U.S. Appl. No. 10/898,527.
82Office Action, mailed Aug. 5, 2003 for U.S. Appl. No. 09/811,081.
83Office Action, mailed Aug. 8, 2008 for U.S. Appl. No. 11/676,273.
84Office Action, mailed Dec. 30, 2003 for U.S. Appl. No. 09/811,081.
85Office Action, mailed Jan. 12, 2005 for U.S. Appl. No. 09/843,597.
86Office Action, mailed Jan. 15, 2008 for U.S. Appl. No. 11/676,273.
87Office Action, mailed Jul. 21, 2005 for U.S. Appl. No. 11/076,251.
88Office Action, mailed Jun. 20, 2006 for U.S. Appl. No. 11/062,109.
89Office Action, mailed Jun. 27, 2007 for U.S. Appl. No. 11/676,273.
90Office Action, mailed Jun. 30, 2004 for U.S. Appl. No. 09/843,597.
91Office Action, mailed Mar. 10, 2006 for U.S. Appl. No. 11/055,559.
92Office Action, mailed May 18, 2004 for U.S. Appl. No. 10/653,876.
93Office Action, mailed May 30, 2008 for U.S. Appl. No. 11/334,039.
94Office Action, mailed Sep. 29, 2006 for U.S. Appl. No. 11/423,856.
95Ofice Action, mailed Jun. 15, 2004 for U.S. Appl. No. 09/811,081.
96Ofice Action, mailed May 24, 2004 for U.S. Appl. No. 10/602,327.
97Ojha et al, Demonstration of low loss integrated InGaAsP/InP demultiplexer device with low polarization sensitivity, Electron. Lett., vol. 29 No. 9 p. 805 (Apr. 1993).
98Paddon et al, Simple approach to Coupling in Textured Planar Waveguides, Opt. Lett., vol. 23 No. 19 pp. 1529-1531 (1998).
99Preston, "Digital holographic logic", Pattern Recognition, vol. 5, p. 37 (1973).
100Rantala et al, Sol-gel hybrid glass diffractive elements by direct electron-beam exposure., Electron. Lett. vol. 34 No. 5 pp. 455-456 (Mar. 1998).
101Reasons for Allowance, mailed Aug. 20, 2007 for U.S. Appl. No. 11/685,212.
102Reasons for Allowance, mailed Aug. 3, 2006 for U.S. Appl. No. 11/361,407.
103Reasons for Allowance, mailed Aug. 5, 2005 for U.S. Appl. No. 10/794,634.
104Reasons for Allowance, mailed Dec. 19, 2006 for U.S. Appl. No. 11/532,532.
105Reasons for Allowance, mailed Dec. 5, 2005 for U.S. Appl. No. 11/239,540.
106Reasons for Allowance, mailed Jan. 24, 2007 for U.S. Appl. No. 10/898,527.
107Reasons for Allowance, mailed Jan. 25, 2007 for U.S. Appl. No. 11/383,494.
108Reasons for Allowance, mailed Jul. 22, 2005 for U.S. Appl. No. 10/923,455.
109Reasons for Allowance, mailed Jun. 12, 2006 for U.S. Appl. No. 11/055,559.
110Reasons for Allowance, mailed Mar. 20, 2007 for U.S. Appl. No. 11/423,856.
111Reasons for Allowance, mailed May 19, 2005 for U.S. Appl. No. 09/843,597.
112Reasons for Allowance, mailed May 6, 2005 for U.S. Appl. No. 10/989,236.
113Reasons for Allowance, mailed Nov. 19, 2004 for U.S. Appl. No. 09/811,081
114Reasons for Allowance, mailed Nov. 19, 2004 for U.S. Appl. No. 10/602,327.
115Reasons for Allowance, mailed Oct. 13, 2006 for U.S. Appl. No. 11/062,109.
116Reasons for Allowance, mailed Oct. 22, 2008 for U.S. Appl. No. 11/334,039.
117Reasons for Allowance, mailed Sep. 15, 2005 for U.S. Appl. No. 10/857,987.
118Reasons for Allowance, mailed Sep. 15, 2005 for U.S. Appl. No. 10/998,185.
119Reasons for Allowance, mailed Sep. 16, 2005 for U.S. Appl. No. 10/842,790.
120Reasons for Allowance, mailed Sep. 23, 2003 for U.S. Appl. No. 10/229,444.
121Salehi, et al., "Coherent Ultrashort Light Pulse Code-Division Multiple Access Communication Systems", Journal of Lightwave Technology vol. 8, pp. 479-491 Mar. 1990.
122Sampson, et al., "Photonic CDMA by Coherent Matched Filtering Using Time-Addressed Coding in Optical Ladder Networks", Journal of Lighwave Technology vol. 12 No. 11, pp. 2001-2010, Nov. 1994.
123Song et al, Focusing-grating-coupler arrays for uniform and efficient signal distribution in a backboard optical interconnect., Appl. Opt., vol. 34 No. 26 pp. 5913-5919 (Sep. 1995).
124Soole et al, High speed monolithic WDM detector for 1.5 mum fibre band., Electron. Lett., vol. 31 No. 15 pp. 1276-1277 (Jul. 1995).
125Soole et al, High speed monolithic WDM detector for 1.5 μm fibre band., Electron. Lett., vol. 31 No. 15 pp. 1276-1277 (Jul. 1995).
126Sudbo et al, Reflectivity of Integrated Optical filters Based on Elliptic Bragg Reflectors., Lighwave Tech., vol. 8 No. 6 pp. 998-1006 (Jun. 1990).
127Sun et al, Demultiplexer with 120 channels and 0.29-nm channel spacing, IEEE Photonics Tech. Lett., vol. 10 No. 1 pp. 90-92 (Jan. 1998).
128Taillaert, et al., Out-of-plane grating coupler for efficient butt-coupling between compact planar waveguides and single-mode fiberts, IEEE J. Quantum Electron., vol. 38, No. 7 (Jul. 2002).
129Takenouchi et al, Analysis of optical-signal processing using an arrayed-waveguide grating., Optics Express, vol. 6 No. 6 pp. 124-135 (Mar. 2000).
130Tang et al, A novel wavelength-division-demultiplexer with optical in-plane to surface-normal conversion, IEEE Photonics Tech. Lett., vol. 7 No. 8 p. 908 (Aug. 1995).
131Taylor, et al., Determination of diffraction efficency for a second-order corrugated waveguide, IEEE J. Quantum Electron., vol. 33, No. 2 (Feb. 1997).
132Tien et al., "Use of Concentric-Arc Grating as a Thin-Film Spectrographic for Guided Waves" Appl. Phys. Lett. vol. 37 No. 6 pp. 524-525 (Sep. 15, 1980).
133Ura et al., "Integrated Optic Wavelength Demultiplexer Using a Coplanar Grating Lens", Applied Optics, vol. 29 No. 9 pp. 1369-1373 (Mar. 20, 1990).
134Wang et al, "Five-Channel Polymer Waveguide Wavelength Division Demultiplexer for the Near Infrared", IEEE Photonics Technology Letters, vol. 3 No. 1 pp. 36-38 (Jan. 1991).
135Wang et al., "Theory and Applications of Guided-Mode Resonance Filters", Applied Optics, vol. 32 No. 14 pp. 2606-2613 (May 10, 1993).
136Wang et al., "Wavelength-Division Multiplexing and Demultiplexing on Locally Sensitized Single-Mode Polymer Microstructure Waveguides", Optics Letters, vol. 15, No. 7, pp. 363-365 (Apr. 1, 1990).
137Weiner, et al., "Femtosecond Spectral Holography" IEEE Journal of Quantum Electronics vol. 28 No. 10, pp. 2251-2261, 1992.
138Wiesman et al., "Apodized Surface-Corrugated Gratings with Varying Duty Cycles", IEEE Photonics Technology Letters, vol. 12 No. 6 pp. 639-641 (Jun. 2000).
139Wu et al., "Simplified Coupled-Wave Equations for Cylindrical Waves in Circular Grating Planar Waveguides", Journal of Lighwave Technology, vol. 10 No. 11 pp. 1575-1589 (Nov. 1992).
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US8451871 *Jun 27, 2011May 28, 2013Vladimir YankovMethod of manufacturing a laser diode with improved light-emitting characteristics
US20110263056 *Jun 27, 2011Oct 27, 2011Nano-Optic Devices, LlcMethod of manufacturing a laser diode with improved light-emitting characteristics
Classifications
U.S. Classification385/37, 385/24, 372/20, 372/102
International ClassificationG02B6/34
Cooperative ClassificationG02B6/12004, G02B6/4214, G02B6/124, G02B6/42, G02B6/12007, G02B2006/12164, G02B6/12019
European ClassificationG02B6/124, G02B6/12M2O, G02B6/12D, G02B6/12M, G02B6/42
Legal Events
DateCodeEventDescription
Jul 5, 2011CCCertificate of correction