Claims
- 1. In a surface emitting distributed feedback laser having a p-type cladding layer with a gain region and a curved grating the improvement wherein the curved grating formed in the gain region comprises a variable radius grating that curves away from a central point near a center of the gain region.
- 2. The laser of claim 1 wherein the curved grating has a grating curvature that is represented by a deformation function L(y, z) whose dominant term has a form corresponding to (-zy.sup.2), wherein z is a dimension along a longitudinal axis of the gain medium and y is a dimension along a transverse axis of the gain medium, and wherein the origin of y and z is located near the center of the gain region.
- 3. The laser of claim 2 wherein the grating deformation function has additional terms that improve output beam quality of the laser, which terms include chirp (z.sup.2) and aberration correction terms (z.sup.3 y.sup.2).
- 4. In a surface emitting distributed feedback laser having a p-type cladding layer with a gain region and a curved grating the improvement wherein the curved grating formed in the gain region comprises a second order, variable radius curved grating that curves away from a center of the gain region.
- 5. The laser of claim 4 wherein the curved grating comprises a variable radius grating that curves from a central point near a center of the gain region.
- 6. The laser of claim 4 wherein the curved grating has a grating curvature that is represented by a deformation function L(y, z) whose dominant term has a form corresponding to (-zy.sup.2), wherein z is a dimension along a longitudinal axis of the gain medium and y is a dimension along a transverse axis of the gain medium, and wherein the origin of y and z is located near the center of the gain region.
- 7. The laser of claim 6 wherein the grating deformation function has additional terms that improve output beam quality of the laser, which terms include chirp (z.sup.2) and aberration correction terms (z.sup.3 y.sup.2).
Parent Case Info
This is a continuation application of Ser. No. 644,672 filed 7 May 1996 now abandoned which is a continuation application of Ser. No. 229,493 filed Apr. 19, 1994, of Steven H. Macomber now abandoned which is a continuation-in-part of Ser. No. 07/974,775, filed Nov. 25, 1992 now U.S. Pat. No. 5,345,466 which is a continuation-in-part Ser. No. 07/975,303, filed Nov. 12, 1992 now U.S. Pat. No. 5,307,183.
Government Interests
This invention was made with Government support under Government Contract No. F29601-C-91-0118 awarded by the Air Force. The Government has certain rights in this invention.
US Referenced Citations (7)
Foreign Referenced Citations (1)
Number |
Date |
Country |
A-0 552 028 |
Jul 1993 |
EPX |
Non-Patent Literature Citations (4)
Entry |
IEEE Journal of Quantum Electronics, vol. 30, No. 1, Jan. 1994, New York, pp. 31-36, R. J. Lang, "Design of aberration-corrected curved-mirror and curved grating unstable resonator diode lasers". |
Proceedings of the Society Of Photo-Optical Instrumentation Engineers (SPIE), vol. 239, 1980, Bellingham, US, pp. 10-18, A. Suzuki, K. Tada, "Theory and experiment on distributed feedback lasers with chirped gratings". (No month available) |
Optics Letters, vol. 1, No. 2, Aug. 1997, Washington, US pp. 64-66, P. K. Tien, "Method of forming novel curved-line gratings and their use as reflectors and resoonators in integrated optics". |
Agrawal and Dutta, Semiconductor Lasers, Van Nostrand Reinhold, New York, pp. 224-226, 1993. |
Continuations (2)
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Number |
Date |
Country |
Parent |
644672 |
May 1996 |
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Parent |
229493 |
Apr 1994 |
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Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
974775 |
Nov 1992 |
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Parent |
975303 |
Nov 1992 |
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