Active wavelength selection with resonant devices

• US 6,215,928 B1
• Filed: 10/25/1999
• Issued: 04/10/2001
• Est. Priority Date: 05/09/1996
• Status: Expired due to Term

• Current Assignee: Yeda Research and Development Co. Ltd. (Weizmann Institute of Science)
• Original Assignee: Yeda Research and Development Co. Ltd. (Weizmann Institute of Science)
• Inventors: Sharon, Avner Zvi, Friesem, Asher A.
• Primary Examiner(s): Lee, John D.
• Application Number:
  US09/180,201
• Time in Patent Office: 533 Days
• Field of Search: 385/2, 385/3, 385/8-10, 385/15, 385/27, 385/37, 385/39, 385/40, 385/129, 385/130, 385/131, 372/20, 372/23, 372/96, 372/102
• US Class Current: 385/37
• CPC Class Codes: G02F 1/025 in an optical waveguide structure G02F1/017, G02F1/2257 take precedence
• CPC Class Codes: G02F 1/035 in an optical waveguide structure
• CPC Class Codes: G02F 1/1326 Liquid crystal optical waveguides or liquid crystal cells specially adapted for gating or modulating between optical waveguides
• CPC Class Codes: G02F 2201/305 diffraction grating
• CPC Class Codes: G02F 2203/055 wavelength filtering
• CPC Class Codes: H01S 3/1055 one of the reflectors being constituted by a diffraction grating
• CPC Class Codes: H01S 5/0285 Coatings with a controllable reflectivity
• CPC Class Codes: H01S 5/141 using a wavelength selective device, e.g. a grating or etalon H01S5/146 takes precedence

Abstract

This invention discloses an electro-optically controlled optical element including a diffraction grating, and a planar waveguide associated with the diffraction grating, the diffraction grating and planar waveguide being configured to undergo resonance of at least one of transmitted or reflected light at a wavelength which is selectable by means of an electrical input.

Claims

1. An electro-optically controlled optical element, comprising:

a diffraction grating; and

a planar waveguide associated with said diffraction grating, said diffraction grating and said planar waveguide constituting a resonant structure, tunable to a preselected wavelength of light by means of an electrical input.

2. An electro-optically controlled optical element according to claim 1 and also comprising a light transmissive medium whose index of refraction is controlled by said electrical input.

3. An electro-optically controlled optical element according to claim 2 and also comprising transparent conductors arranged adjacent said light transmissive medium and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said light transmissive medium.

4. An electro-optically controlled optical element according to claim 2 and wherein said light transmissive medium is a liquid crystal material.

5. An electro-optically controlled optical element according to claim 4 and wherein said light transmissive medium has an index of refraction which is controlled by said electrical input and said optical element also comprises transparent conductors arranged adjacent said light transmissive medium and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said light transmissive medium.

6. An electro-optically controlled optical element according to claim 1 and wherein said planar waveguide has an index of refraction which is controlled by said electrical input.

7. An electro-optically controlled optical element according to claim 6 and also comprising transparent conductors arranged adjacent said planar waveguide and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said planar waveguide.

8. An electro-optically controlled optical element according to claim 1 and wherein said diffraction grating and said planar waveguide are formed of semiconductor materials.

9. An electro-optically controlled optical element according to claim 8 and also comprising a light transmissive medium whose index of refraction is controlled by said electrical input and transparent conductors arranged adjacent said light transmissive medium and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy via suitably doped semiconductor material across said light transmissive medium.

10. An electro-optically controlled optical element according to claim 8 wherein said planar waveguide has an index of refraction which is controlled by said electrical input and also comprising transparent conductors arranged adjacent said planar waveguide and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy via suitably doped semiconductor material across said planar waveguide.

11. An electro-optically controlled optical element according to claim 1 and wherein at least one of said diffraction grating and said planar waveguide are formed of an electro-optical material.

12. An electro-optically controlled optical element according to claim 11 and also comprising a light transmissive medium whose index of refraction is controlled by said electrical input and transparent conductors arranged adjacent said light transmissive medium and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said light transmissive medium.

13. An electro-optically controlled optical element according to claim 11 wherein said planar waveguide has an index of refraction which is controlled by said electrical input and also comprising transparent conductors arranged adjacent said planar waveguide and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said planar waveguide.

14. An electro-optically controlled optical element according to claim 1 and wherein at least one of said diffraction grating and said planar waveguide are formed of at least one of a polymeric material and a liquid crystal.

15. An electro-optically controlled optical element according to claim 14 and also comprising a light transmissive medium whose index of refraction is controlled by said electrical input and transparent conductors arranged adjacent said light transmissive medium and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said light transmissive medium.

16. An electro-optically controlled optical element according to claim 14 wherein said planar waveguide has an index of refraction which is controlled by said electrical input and also comprising transparent conductors arranged adjacent said planar waveguide and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said planar waveguide.

17. An electro-optically controlled optical element according to claim 1 and wherein said planar waveguide comprises multiple layers having differing indices of refraction.

18. An electro-optically controlled optical element according to claim 1 and having at least one light transmissive surface generally parallel to said planar waveguide and comprising an anti-reflection coating formed on at least one light transmissive surface.

19. An electro-optically controlled optical element according to claim 1 and wherein said optical element is an electro-optical tunable filter.

20. An electro-optically controlled optical element according to claim 1 and wherein said optical element is a portion of a laser.

21. An electro-optically controlled optical element according to claim 1, and which is operative to transmit incident light essentially only at said preselected wavelength.

22. An electro-optically controlled optical element according to claim 1, and which is operative to reflect incident light essentially only at said preselected wavelength.

23. An electro-optically controlled optical element according to claim 1, and wherein said diffraction grating essentially covers the entire width of the element.

24. A laser comprising:

a laser cavity; and

an active tunable mirror and an output coupler defining said laser cavity, and wherein said active tunable mirror comprises an electro-optically controlled optical element comprising;

a diffraction grating; and

a planar waveguide associated with said diffraction grating, said diffraction grating and said planar waveguide constituting a resonant structure, tunable to a preselected wavelength of light by means of an electrical input.

25. A laser according to claim 24 and wherein said electro-optically controlled optical element also comprises a light transmissive medium whose index of refraction is controlled by said electrical input.

26. A laser according to claim 25 and wherein said electro-optically controlled optical element also comprises transparent conductors arranged adjacent said light transmissive medium and electro-optically connected via, electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said light transmissive medium.

27. A laser according to claim 24 and wherein said planar waveguide has an index of refraction which is controlled by said electrical input.

28. A laser according to claim 27 and wherein said electro-optically controlled optical element also comprises transparent conductors arranged adjacent said planar waveguide and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said planar waveguide.

29. A laser according to claim 24 and wherein said diffraction grating and said planar waveguide are formed of semiconductor materials.

30. A laser according to claim 29 and wherein said electro-optically controlled optical element also comprises a light transmissive medium whose index of refraction is controlled by said electrical input and transparent conductors arranged adjacent said light transmissive medium and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy via suitably doped semiconductor material across said light transmissive medium.

31. A laser according to claim 29 wherein said planar waveguide has an index of refraction which is controlled by said electrical input and wherein said electro-optically controlled optical element also comprises transparent conductors arranged adjacent said planar waveguide and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy via suitably doped semiconductor material across said planar waveguide.

32. A laser according to claim 24 and wherein at least one of said diffraction grating and said planar waveguide are formed of an electro-optical material.

33. A laser according to claim 32 and wherein said electro-optically controlled optical element also comprises a light transmissive medium whose index of refraction is controlled by said electrical input and transparent conductors arranged adjacent said light transmissive medium and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said light transmissive medium.

34. A laser according to claim 32 wherein said planar waveguide has an index of refraction which is controlled by said electrical input and wherein said electro-optically controlled optical element also comprises transparent conductors arranged adjacent said planar waveguide and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said planar waveguide.

35. A laser according to claim 34 and wherein at least one of said diffraction grating and said planar waveguide are formed of at least one of a polymeric material and a liquid crystal.

36. A laser according to claim 35 and wherein said electro-optically controlled optical element also comprises a light transmissive medium whose index of refraction is controlled by said electrical input, and transparent conductors arranged adjacent said light transmissive medium and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said light transmissive medium.

37. A laser according to claim 36 and wherein said light transmissive medium is a liquid crystal material.

38. A laser according to claim 37 and wherein said light transmissive medium has an index of refraction which is controlled by said electrical input and said optical element also comprises transparent conductors arranged adjacent said light transmissive medium and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said light transmissive medium.

39. A laser according to claim 35 wherein said planar waveguide has an index of refraction which is controlled by said electrical input and wherein said electro-optically controlled optical element also comprises transparent conductors arranged adjacent said planar waveguide, and electro-optically connected via electrodes to said electrical input, said transparent conductors being operative to apply electrical energy across said planar waveguide.

40. A laser according to claim 24 and wherein said planar waveguide comprises multiple layers having differing indices of refraction.

41. A laser according to claim 24 and wherein said electro-optically controlled optical element also comprises at least one light transmissive surface generally parallel to said planar waveguide and comprising an anti-reflection coating formed on said at least one light transmissive surface.

42. A laser according to claim 24 and tunable by means of an electric input over a dynamic range of at least 0.1 nanometer.

43. A laser according to claim 24 and tunable by means of an electric input over a dynamic range of at least 1 nanometer.

44. A laser according to claim 24 and tunable by means of an electric input over a dynamic range of several tens of nanometers.