Laser wavelength actuators

• US 20060092996A1
• Filed: 10/28/2004
• Published: 05/04/2006
• Est. Priority Date: 10/28/2004
• Status: Active Grant

• Current Assignee: Newport Corporation (MKS Instruments Incorporated)
• Original Assignee: Bookham Incorporated (Oclaro (North America), Inc.)
• Inventors: Wang, Weizhi, Nguyen, Hoang Tan
• Granted Patent: US 7,286,577 B2
• Time in Patent Office: Days
• US Class Current: 372/20
• CPC Class Codes: H01S 3/1065 using liquid crystals
• CPC Class Codes: H01S 5/141 using a wavelength selective device, e.g. a grating or etalon H01S5/146 takes precedence
• CPC Class Codes: H01S 5/143 Littman-Metcalf configuration, e.g. laser - grating - mirror

Abstract

A laser-emitting device may be coupled to an electro-optically controlled wavelength actuator. An electro-optically controlled wavelength actuator may be a holographic wavelength actuator or a liquid crystal wavelength actuator. The electro-optically controlled wavelength actuator may function as a tunable diffraction grating for external cavity lasers.

Claims

1. A laser output device, comprising:

a laser emitting device configured to provide a laser output; and

a holographic wavelength actuator optically coupled to the laser emitting device,

wherein the holographic wavelength actuator comprises;

an electro-optic crystal; and

a holographic material coupled to the electro-optic crystal;

wherein one or more properties of the holographic wavelength actuator are configured to be adjusted to select and tune a wavelength of the laser output.

2. The laser output device of claim 1, wherein the laser emitting device comprises a laser emitting diode.

3. The laser output device of claim 1, wherein the laser output device is located in a laser cavity.

4. The laser output device of claim 1, wherein the laser output device is located in a Littrow laser cavity or Littman-Metcalf cavity configuration.

5. The laser output device of claim 1, wherein the electro-optic crystal comprises LiNbO₃.

6. The laser output device of claim 1, wherein the holographic material is coupled directly to a surface of the electro-optic crystal.

7. The laser output device of claim 1, wherein the holographic material is coupled to a surface of the electro-optic crystal in a volume configuration.

8. The laser output device of claim 1, further comprising glass coupled to the holographic material.

9. The laser output device of claim 1, wherein the holographic material is coupled to a surface of the electro-optic crystal in a surface relief configuration.

10. The laser output device of claim 1, further comprising at least one collimating lens.

11. The laser output device of claim 1, wherein the one or more properties of the holographic wavelength are configured to be adjusted to select an axial mode of the laser output and an optical path length of the laser output.

12. The laser output device of claim 1, wherein at least one of the adjustable properties comprises an index of refraction of the electro-optic crystal.

13. The laser output device of claim 1, wherein the holographic wavelength actuator is configured to perform as a diffraction grating, and wherein at least one of the adjustable properties comprises a grating diffraction center wavelength of the holographic wavelength actuator.

14. The laser output device of claim 1, wherein the holographic wavelength actuator is configured to perform as a diffraction grating, and wherein the adjustable properties comprises an index of refraction of the electro-optic crystal and a grating diffraction center wavelength of the holographic wavelength actuator.

15. The laser output device of claim 1, wherein the electro-optic crystal is configured to adjust the properties of the holographic material.

16. The laser output device of claim 1, wherein the holographic wavelength actuator is configured to perform as a diffraction grating, and wherein electro-optic crystal controls a grating angle of the diffraction grating depicted in the holographic material to select and tune the wavelength of the laser output.

17. The laser output device of claim 1, wherein the electro-optic crystal and the holographic wavelength actuator are configured to actively correct for mode hop in the laser output.

18. The laser output device of claim 1, wherein the electro-optic crystal and the holographic wavelength actuator are configured to stabilize the wavelength of the laser output.

19. A method for wavelength selection and tuning, comprising:

providing a laser output from a laser emitting device; and

selecting and tuning a wavelength of the laser output by adjusting one or more properties of a holographic wavelength actuator optically coupled to the laser emitting device.

20. The method of claim 19, further comprising correcting for active mode hopping using the holographic wavelength actuator.

21. The method of claim 19, further comprising controlling the properties of the holographic wavelength actuator using the electro-optic crystal.

22. The method of claim 19, wherein the holographic wavelength actuator is configured to perform as a diffraction grating, and wherein the method further comprises selecting and tuning the wavelength of the laser output by adjusting an index of refraction of the electro-optic crystal and a grating diffraction center wavelength of the diffraction grating depicted in the holographic material.

23. The method of claim 19, further comprising adjusting the properties of the holographic wavelength actuator to select an axial mode of the laser cavity.

24. A laser output device, comprising:

a laser emitting device configured to provide a laser output; and

a liquid crystal wavelength actuator optically coupled to the laser emitting device,

wherein the liquid crystal wavelength actuator comprises;

an electro-optic crystal; and

a liquid crystal display material coupled to the electro-optic crystal;

wherein one or more properties of the liquid crystal wavelength actuator are configured to be adjusted to select and tune a wavelength of the laser output.

25. The laser output device of claim 24, wherein the laser output device comprises a laser cavity.

26. The laser output device of claim 24, wherein the liquid crystal wavelength actuator is configured to perform as a diffraction grating.

27. The laser output device of claim 24, wherein the laser emitting device comprises a laser emitting diode.

28. The laser output device of claim 24, wherein the liquid crystal wavelength actuator is substantially optically reflective.

29. The laser output device of claim 24, wherein the liquid crystal wavelength actuator is substantially optically transmissive.

30. The laser output device of claim 24, wherein the liquid crystal wavelength actuator is configured to select a wavelength for the laser output device.

31. The laser output device of claim 24, wherein the liquid crystal wavelength actuator is configured to select and tune a wavelength for the laser output device.

32. The laser output device of claim 24, wherein the liquid crystal wavelength actuator is configured to perform as a diffraction grating, and wherein the liquid crystal wavelength actuator is configured to tune a wavelength for the laser output device by adjustment of the grating period of the liquid crystal wavelength actuator.

33. The laser output device of claim 24, wherein the liquid crystal wavelength actuator is configured to actively compensate for mode hop in the laser output device.

34. The laser output device of claim 24, wherein the liquid crystal wavelength actuator is configured to compensate for active mode hop in the laser output device by adjustment of the period of the wavelength actuator.

35. The laser output device of claim 24, wherein the liquid crystal wavelength actuator is configured to stabilize a wavelength of the laser output device.

36. The laser output device of claim 24, wherein the laser emitting device and the liquid crystal wavelength actuator are coupled in a Littrow laser configuration.

37. The laser output device of claim 24, wherein the laser emitting device and the liquid crystal wavelength actuator are coupled in a Littman-Metcalf laser configuration.

38. The laser output device of claim 24, further comprising at least one collimating lens.

39. A method for laser output wavelength tuning, comprising:

providing a laser output from a laser emitting device; and

selecting and tuning a wavelength of the laser output by adjusting one or more properties of a liquid crystal wavelength actuator optically coupled to the laser emitting device.

40. The method of claim 39, further comprising selecting a wavelength of the laser output using the liquid crystal wavelength actuator.

41. The method of claim 39, wherein the liquid crystal wavelength actuator is configured to perform as a diffraction grating, and wherein the method further comprises selecting a wavelength of the laser output by adjusting the grating period and an index of refraction of the liquid crystal wavelength actuator.

42. The method of claim 39, wherein the liquid crystal wavelength actuator is configured to perform as a diffraction grating, and wherein the method further comprises adjusting the period of the liquid crystal wavelength actuator by varying a current applied to the wavelength actuator.

43. The method of claim 39, further comprising collimating at least some of the laser output.

44. The method of claim 39, wherein the laser emitting device comprises a laser emitting diode.

45. The method of claim 39, wherein the liquid crystal wavelength actuator is substantially optically transmissive.

46. The method of claim 39, wherein the liquid crystal wavelength actuator is substantially optically reflective.

47. The method of claim 39, further comprising stabilizing the wavelength of the laser output using the liquid crystal wavelength actuator.

48. A laser output device, comprising:

A laser emitting device configured to provide a laser output; and

an electro-optically controlled wavelength actuator optically coupled to the laser emitting device;

wherein the wavelength of light output by the laser output device is controlled by the electro-optically controlled wavelength actuator during use.

49. A method for laser output wavelength tuning, comprising:

providing a laser output from a laser emitting device; and

selecting and tuning a wavelength of the laser output by adjusting one or more properties of an electro-optically controlled wavelength actuator optically coupled to the laser emitting device.