Enhancing the sensitivity of resonant optical modulating and switching devices

1. A method for manipulating an optical beam, having a bandwidth centered about λ 1 , said method comprising:

propagating an optical beam along a first waveguide;

attenuating the optical beam in said first waveguide by inducing destructive interference with a resonant cavity proximal to said first waveguide, said resonant cavity comprising a medium optically transmissive to said optical beam and having an effective refractive index, n;

modulating said attenuation induced in said first waveguide by tuning and detuning said resonant cavity using a first effect, said tuning and detuning accomplished by varying a modulation signal applied to said resonant cavity to alter the effective refractive index, n, of said medium in said tunable resonant cavity; and

increasing the sensitivity of the tunable resonant cavity to said modulation signal using a second effect, the second effect being different from the first effect, wherein the second effect comprises providing optical energy of sufficient intensity within the resonant cavity to induce a non-linear optical effect in the medium in said resonant cavity.

2. The method of claim 1 , further comprising switching at least a portion of said optical beam from said first waveguide to a second waveguide, also proximal to said resonant cavity.

3. The method of claim 1 , wherein applying said modulation signal comprises applying an electric modulation signal to said resonant cavity.

4. The method of claim 3 , wherein said electric signal has a voltage less than one volt.

5. The method of claim 3 , wherein said electric signal has a voltage less than 500 millivolts.

6. The method of claim 3 , wherein said electric signal has a voltage less than 200 millivolts.

7. The method of claim 1 , wherein said optical beam is modulated using an extinction ratio of at least about 6 dB.

8. The method of claim 1 , wherein said optical beam is modulated using an extinction ratio of about 10 dB.

9. The method of claim 1 , wherein at least one of said first waveguide and said resonant cavity comprises silicon.

10. A method for manipulating an optical beam, having a bandwidth centered about λ 1 , said method comprising:

propagating an optical beam along a first waveguide;

attenuating the optical beam in said first waveguide by inducing destructive interference with a resonant cavity proximal to said first waveguide, said resonant cavity comprising a medium optically transmissive to said optical beam and having an effective refractive index, n, wherein said resonant cavity has a resonant frequency band defined by a low wavelength cutoff and a high wavelength cutoff, and said resonant cavity is operated so that the center wavelength, λ 1 , of said optical beam is nearer to said high wavelength cutoff than said low wavelength cutoff;

modulating said attenuation induced in said first waveguide by tuning and detuning said resonant cavity, said tuning and detuning accomplished by varying a modulation signal applied to said resonant cavity to alter the effective refractive index, n, of said medium in said tunable resonant cavity; and

increasing the sensitivity of said tunable resonant cavity to said modulation signal by providing optical energy of sufficient intensity within the resonant cavity to induce a non-linear optical effect in the medium in said resonant cavity.

11. The method of claim 10 , wherein tuning and detuning said resonant cavity comprises shifting said resonant frequency band relative to wavelength, λ 1 .

12. The method of claim 10 , wherein inducing said non-linear optical effect causes a steepening of the high wavelength portion of the resonant band.

13. The method of claim 1 , wherein providing optical energy of sufficient intensity within the resonant cavity to induce said non-linear optical effect in the medium in said resonant cavity comprises increasing the power level of said optical beam to about 8 dBm.

14. The method of claim 1 , further comprising propagating a pump beam in said resonant cavity to provide said optical energy of sufficient intensity within the resonant cavity to induce said non-linear optical effect in the medium of said resonant cavity.

15. The method of claim 1 , wherein said optical energy that is provided in said resonant cavity comprises a continuous wave optical signal.

16. The method of claim 1 , wherein said optical energy that is provided in said resonant cavity is amplitude modulated between intensity levels that are insufficient to induce said non-linear optical effect in the medium in said resonant cavity and intensity levels that are sufficient to induce said non-linear optical effect in the medium in said resonant cavity.

17. The method of claim 14 , wherein said pump beam comprises a continuous wave optical signal.

18. The method of claim 14 , wherein said pump beam comprises a modulated optical signal.

19. The method of claim 1 , wherein said non-linear optical effect comprises a X (3) non-linear optical effect.

20. The method of claim 19 , wherein said X (3) non-linear optical effect comprises the Kerr effect.

21. The method of claim 1 , further comprising coupling said optical beam into said resonant cavity, and setting the power of said optical beam to a level such that it is of sufficient intensity to induce said non-linear optical effect in the medium in said resonant cavity after coupling into said resonant cavity.

22. The method of claim 1 , wherein using the first effect comprises causing charge carriers within the resonant cavity to be redistributed.

23. The method of claim 1 , wherein using the first effect comprises modulating the width of a depletion region.

24. The method of claim 1 , wherein using the first effect comprises modulating the width of an inversion layer.

25. The method of claim 10 , further comprising switching at least a portion of said optical beam from said first waveguide to a second waveguide, also proximal to said resonant cavity.

26. The method of claim 10 , wherein applying said modulation signal comprises applying an electric modulation signal to said resonant cavity.

27. The method of claim 26 , wherein said electric signal has a voltage less than one volt.

28. The method of claim 26 , wherein said electric signal has a voltage less than 500 millivolts.

29. The method of claim 26 , wherein said electric signal has a voltage less than 200 millivolts.

30. The method of claim 10 , wherein said optical beam is modulated using an extinction ratio of at least about 6 dB.

31. The method of claim 10 , wherein said optical beam is modulated using an extinction ratio of about 10 dB.

32. The method of claim 10 , wherein at least one of said first waveguide and said resonant cavity comprises silicon.

33. The method of claim 10 , wherein providing optical energy of sufficient intensity within the resonant cavity to induce said non-linear optical effect in the medium in said resonant cavity comprises increasing the power level of said optical beam to about 8 dBm.

34. The method of claim 10 , further comprising propagating a pump beam in said resonant cavity to provide said optical energy of sufficient intensity within the resonant cavity to induce said non-linear optical effect in the medium of said resonant cavity.

35. The method of claim 34 , wherein said pump beam comprises a continuous wave optical signal.

36. The method of claim 34 , wherein said pump beam comprises a modulated optical signal.

37. The method of claim 10 , wherein said optical energy that is provided in said resonant cavity comprises a continuous wave optical signal.

38. The method of claim 10 , wherein said optical energy that is provided in said resonant cavity is amplitude modulated between intensity levels that are insufficient to induce said non-linear optical effect in the medium in said resonant cavity and intensity levels that are sufficient to induce said non-linear optical effect in the medium in said resonant cavity.

39. The method of claim 10 , wherein said non-linear optical effect comprises a X (3) non-linear optical effect.

40. The method of claim 39 , wherein said X (3) non-linear optical effect comprises the Kerr effect.

41. The method of claim 10 , further comprising coupling said optical beam into said resonant cavity, and setting the power of said optical beam to a level such that it is of sufficient intensity to induce said non-linear optical effect in the medium in said resonant cavity after coupling into said resonant cavity.

42. The method of claim 10 , wherein modulating said attenuation by tuning and detuning said resonant cavity comprises causing charge carriers within said resonant cavity to be redistributed.

43. The method of claim 10 , wherein modulating said attenuation by tuning and detuning said resonant cavity comprises modulating the width of a depletion region.

44. The method of claim 10 , wherein modulating said attenuation by tuning and detuning said resonant cavity comprises modulating the width of an inversion layer.