Vertical cavity surface emitting laser that uses intracavity degenerate four wave mixing to produce phase-conjugated and distortion free collimated laser light

• US 6,625,195 B1
• Filed: 07/20/1999
• Issued: 09/23/2003
• Est. Priority Date: 07/20/1999
• Status: Expired due to Fees

• Current Assignee: Joseph Reid Henrichs
• Original Assignee: Joseph Reid Henrichs
• Inventors: Henrichs, Joseph Reid
• Primary Examiner(s): DAVIE, JAMES W
• Application Number:
  US09/357,685
• Time in Patent Office: 1,526 Days
• Field of Search: 372/45, 372/46, 372/50, 372/96, 372/92, 372/99
• US Class Current: 372/96
• CPC Class Codes: H01S 3/08059 Constructional details of the reflector, e.g. shape mirrors in general G02B5/08; mountings for mirrors G02B7/18
• CPC Class Codes: H01S 3/109 Frequency multiplication, e.g. harmonic generation
• CPC Class Codes: H01S 5/0604 comprising a non-linear region, e.g. generating harmonics of the laser frequency
• CPC Class Codes: H01S 5/145 Phase conjugate mirrors
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/18369 based on dielectric materials
• CPC Class Codes: H01S 5/423 having a vertical cavity
• CPC Class Codes: H01S 5/426 Vertically stacked cavities

Abstract

The present invention is a “Vertical Cavity Surface Emitting Laser” or “VCSEL” design, wherein the VCSEL device produces phase-conjugated distortion free (reversal of intracavity distortions like diffraction, divergence, and light scattering) and collimated (plane-parallel phase fronts) laser-light emissions. Moreover, through what is called intracavity degenerative four-wave mixing (called four-wave mixing because traditionally there are four frequencies of phase-matched laser light involved in the phase-conjugate process), that occurs within the nonlinear materials of the “Phase Conjugated Vertical Cavity Surface Emitting Laser” or “PCVCSEL” device'"'"'s vertical-cavity. Moreover, these nonlinear materials are located at the center of the PCVCSEL'"'"'s vertical-cavity, wherein wave fronts produced by the PCVCSEL'"'"'s two active-area laser pumps (called Pump 1 and Pump 2) will intersect with wave fronts produced by the PCVCSEL'"'"'s two active-area laser probes (called Probe 1 and Probe 2), therein causing small and large spatial interference-gratings to form, which will ultimately form what is called a “phase conjugate mirror”. Furthermore, the semiconductor materials used in the PCVCSEL'"'"'s vertical-cavity design must exhibit a nonlinear property, called the “third order susceptibility”, which is necessary for the production of a “phase conjugate mirror”. In-addition, materials that exhibit nonlinear third-order susceptibilities are not limited to semiconductor materials like (GaAs) or “Gallium-Arsenide”. (InAs) or “Indium-Arsenide”, (InP) or “Indium-Phosphide”, and (GaSb) or “Gallium-Antimonide”, moreover the ternary semiconductor materials having a Cubic crystal-symmetry of class-F43m and a space-group of “216”; but are also exhibited in photo-refractive materials like (KDP) or “Potassium-Dihydrogen-Phosphate”, and (ADP) or “Ammonium-Dihydrogen-Phosphate”, moreover the photo-refractive materials having a Tetragonal crystal-symmetry of class-142d and a space-group of “122”. Therefore, the photo-refractive materials that also exhibit nonlinear third-order susceptibilities can also be used in the center of the PCVCSEL'"'"'s vertical-cavity design for producing phase-conjugated and distortion free optical radiation emissions.

Claims

1. A semiconductor laser, comprising:

a first reflector assembly having an upper face;

a second reflector assembly having a lower face that faces the upper face of the first reflector assembly; and

a phase conjugator between the first and second reflector assemblies, the phase conjugator including;

a first semiconductor active region parallel to the upper face of the first reflector assembly and the lower face of the second reflector assembly;

a second semiconductor active region that is not parallel to the first semiconductor active region wherein the second semiconductor active region is between the first semiconductor active region and the lower face of the second reflector assembly; and

a third semiconductor active region that is not parallel to the first semiconductor active region and wherein the third semiconductor active region is between the first semiconductor active region and the upper face of the first reflector assembly.

2. The semiconductor laser of claim 1, wherein the phase conjugator includes a reflective phase conjugator.

3. The semiconductor laser of claim 1, wherein the phase conjugator includes a transmissive phase conjugator.

4. The semiconductor laser of claim 1, wherein each semiconductor active region includes a nonlinear semiconductor layer.

5. The semiconductor laser of claim 4, wherein the nonlinear semiconductor layer includes a semiconductor material selected from the group consisting of Gallium-Arsenide, Indium-Arsenide, Indium-Phosphide, and Gallium-Antimonide.

6. The semiconductor laser of claim 4, wherein the nonlinear semiconductor layer includes a photorefractive material.

7. The semiconductor laser of claim 6, wherein the photorefractive material is selected from the group consisting of Potassium-Dihydrogen-Phosphate and Ammonium-Dihydrogen-Phosphate.

8. The semiconductor laser of claim 6, wherein the photorefractive material includes a material having a tetragonal crystal-symmetry of class 142d and a space-group of 122.

9. The semiconductor laser of claim 1, wherein the second semiconductor active region is concave shaped and the third semiconductor active region is convex shaped.

10. The semiconductor laser of claim 1, wherein the phase conjugator further includes a fourth semiconductor active region that is parallel to the first semiconductor active region and wherein the fourth semiconductor active region is between the second and third semiconductor active regions.

11. The semiconductor laser of claim 1, wherein the phase conjugator is provided by non-linear four-wave mixing of optical energy oscillating between the first and second reflector assemblies.

12. The semiconductor laser of claim 1, wherein the first semiconductor active region and the second semiconductor active region share a common contact layer.

13. The semiconductor laser of claim 12, wherein the common contact layer includes Gallium-Arsenide.

14. The semiconductor laser of claim 12, wherein the common contact layer includes p+ doped Gallium-Arsenide.

15. The semiconductor laser of claim 1, wherein the first reflector includes a corner cube prism assembly.

16. The semiconductor laser of claim 15, wherein the corned cube prism assembly includes fused silica.

17. The semiconductor laser of claim 15, wherein the second reflector assembly includes a mirror stack.

18. The semiconductor laser of claim 17, wherein the mirror stack comprises a plurality of dielectric layers.

19. The semiconductor laser of claim 17, wherein the second reflector assembly includes a Distributed Bragg Reflector.

20. The semiconductor laser of claim 1, wherein each semiconductor active region includes an active area, and wherein each active area includes at least one nonlinear semiconductor layer.

21. The semiconductor laser of claim 20, wherein at least one of the active areas includes a single quantum well.

22. The semiconductor laser of claim 20, wherein at least one of the active areas includes a multi-quantum well.

23. The semiconductor laser of claim 10, wherein each semiconductor active region includes an active area, and wherein each of the active areas includes a multi-quantum well.

24. The semiconductor laser of claim of claim 17, wherein each semiconductor region includes an active area, and wherein at least one of the active areas includes a multi-quantum well.

25. The semiconductor laser of claim 24, wherein the multi-quantum well includes:

a plurality of quantum well layers; and

a plurality of quantum well cladding layers, wherein one quantum well cladding layer is between each pair of adjacent quantum well layers.

26. The semiconductor laser of claim 25, wherein:

each of the plurality of quantum well layers include Gallium Arsenide; and

each of the quantum well cladding layers includes Gallium-Aluminum-Arsenide.

27. The semiconductor laser of claim 17, wherein each semiconductor active region includes a multi-quantum well active area.

28. The semiconductor laser of claim 27, wherein each of the multi-quantum wells includes:

a plurality of quantum well layers; and

a plurality of quantum well cladding layers, wherein one quantum well cladding layer is between each pair of adjacent quantum well layers.

29. The semiconductor laser of claim 28, wherein:

each of the plurality of quantum well layers include Gallium Arsenide; and

each of the quantum well cladding layers includes Gallium-Aluminum-Arsenide.

30. The semiconductor laser of claim 1, wherein the first semiconductor active region is between the second and third semiconductor active regions.

31. The semiconductor laser of claim 10, wherein the first and fourth semiconductor active regions are between the second and third semiconductor active regions.

32. The semiconductor laser of claim 31, wherein the second semiconductor active region is concave shaped and the third semiconductor active region is convex shaped.

33. A semiconductor laser, comprising:

a first reflector assembly having an upper face;

a second reflector assembly having a lower face that faces the upper face of the first reflector assembly; and

means, between the first and second reflector assemblies, for providing a phase conjugator between the first and second reflector assemblies, wherein the means for providing a phase conjugator includes at least two semiconductor active regions that are each not parallel to the upper face of the first reflector assembly.

34. The semiconductor laser of claim 33, wherein the means for providing a phase conjugator includes means for providing a reflective phase conjugator.

35. The semiconductor laser of claim 33, wherein the means for providing a phase conjugator includes means for providing a transmissive phase conjugator.

36. The semiconductor laser of claim 33, wherein the means for providing a phase-conjugate mirror include means for providing a four-wave mixing of optical energy oscillating between the first and second reflector assemblies.

37. The semiconductor laser of claim 33, wherein the first reflector includes a comer cube prism assembly.

38. The semiconductor laser of claim 37, wherein the corner cube prism assembly includes fused silica.

39. The semiconductor laser of claim 37, wherein the second reflector assembly includes a mirror stack.

40. The semiconductor laser of claim 39, wherein the mirror stack comprises a plurality of dielectric layers.

41. The semiconductor laser of claim 39, wherein the second reflector assembly includes a Distributed Bragg Reflector.

42. A vertical cavity surface emitting laser, comprising

a first reflector assembly having an upper face;

a second reflector assembly having a lower face facing the upper face of the first reflector assembly, the first and second reflector assemblies defining a resonant cavity; and

a phase conjugator between the first and second reflector assemblies, the phase conjugator including;

a first semiconductor active region parallel to the upper face of the first reflector assembly and the lower face of the second reflector assembly;

a second semiconductor active region that is not parallel to the first semiconductor active region, wherein the second semiconductor active region is between the first semiconductor active region and the lower face of the second reflector assembly; and

a third semiconductor active region that is not parallel to the first semiconductor active region and wherein the third semiconductor active region is between the first semiconductor active region and the upper face of the first reflector assembly.

43. The vertical cavity surface emitting laser of claim 42, wherein the phase conjugator includes a reflective phase conjugator.

44. The vertical cavity surface emitting laser of claim 42, wherein the phase conjugator includes a transmissive phase conjugator.

45. The vertical cavity surface emitting laser of claim 42, wherein the phase conjugator comprises an interference grating produced by four-wave mixing of optical energy oscillating between the first and second reflector assemblies.

46. The vertical cavity surface emitting laser of claim 42, wherein the first semiconductor active region and the second semiconductor active region share a common contact layer.

47. The vertical cavity surface emitting laser of claim 46, wherein the common contact layer includes Gallium-Arsenide.

48. The vertical cavity surface emitting laser of claim 42, wherein the first reflector includes a corner cube prism assembly.

49. The vertical cavity surface emitting laser of claim 48, wherein the second reflector assembly includes a mirror stack.

50. The vertical cavity surface emitting laser of claim 49, wherein each semiconductor active region includes an active area, wherein each active area includes at least one nonlinear semiconductor layer.

51. The vertical cavity surface emitting laser of claim 49, wherein each semiconductor active region includes a multi-quantum well.

52. The vertical cavity surface emitting laser of claim 51, wherein each of the multi-quantum wells includes:

a plurality of quantum well layers; and

a plurality of quantum well cladding layers, wherein one quantum well cladding layer is between each pair of adjacent quantum well layers.

53. The vertical cavity surface emitting laser of claim 52, wherein:

each of the plurality of quantum well layers include Gallium Arsenide; and

each of the quantum well cladding layers includes Gallium-Aluminum-Arsenide.

54. The vertical cavity surface emitting laser of claim 42, wherein the second semiconductor active region is concave shaped and the third semiconductor active region is convex shaped.

55. The vertical cavity surface emitting laser of claim 42, wherein the phase conjugator further includes a fourth semiconductor active region that is parallel to the first semiconductor active region and wherein the fourth semiconductor active region is between the second and third semiconductor active regions.

56. A device, comprising an array of semiconductor lasers, wherein each semiconductor laser includes:

a first reflector assembly having an upper face;

second reflector assembly having a lower face facing the upper face of the first reflector assembly; and

a phase conjugator between the first and second reflector assemblies, the phase conjugator including;

a first semiconductor active region parallel to the upper face of the first reflector assembly and the lower face of the second reflector assembly;

a second semiconductor active region that is not parallel to the first semiconductor active region and wherein the second semiconductor active region is between the first semiconductor active region and the lower face of the second reflector assembly; and

a third semiconductor active region that is not parallel to the first semiconductor active region and wherein the third semiconductor active region is between the first semiconductor active region and the upper face of the lower reflector assembly.

57. The device of claim 56, wherein the phase conjugator includes a reflective phase conjugator.

58. The device of claim 56, wherein the phase conjugator includes a transmissive phase conjugator.

59. The device of claim 56, wherein each semiconductor active region includes a nonlinear semiconductor layer.

60. The device of claim 56, wherein the semiconductor lasers of the array are simultaneously addressable.

61. The device of claim 56, wherein the semiconductor lasers of the array are individually addressable.

62. The device of claim 56, wherein the second semiconductor active region is concave shaped and the third semiconductor active region is convex shaped.

63. The device of claim 56, herein the phase conjugator further includes a fourth semiconductor active region that is parallel to the first semiconductor active region and wherein the fourth semiconductor active region is between the second and third semiconductor active regions.