Nanometer-scale silicon-on-insulator photonic componets

• US 5,838,870 A
• Filed: 02/28/1997
• Issued: 11/17/1998
• Est. Priority Date: 02/28/1997
• Status: Expired due to Fees

• Current Assignee: United States Air Force (Government of the United States of America)
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Soref, Richard A.
• Primary Examiner(s): Palmer, Phan T. H.
• Application Number:
  US08/808,924
• Time in Patent Office: 627 Days
• Field of Search: 385/131, 385/14, 385/42, 385/44, 385/49, 385/50, 385/130, 385/129, 365/150, 365/182, 257/257, 257/335, 257/347, 257/369, 257/487
• US Class Current: 385/131
• CPC Class Codes: G02B 2006/12061 Silicon
• CPC Class Codes: G02B 2006/12121 Laser
• CPC Class Codes: G02B 2006/12128 Multiple Quantum Well [MQW]
• CPC Class Codes: G02B 2006/12195 Tapering
• CPC Class Codes: G02B 6/12004 Combinations of two or more optical elements
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/305 and having an integrated mode-size expanding section, e.g. tapered waveguide
• CPC Class Codes: G02B 6/34 utilising prism or grating G02B6/293 takes precedence
• CPC Class Codes: G02F 1/0152 using free carrier effects, e.g. plasma effect
• CPC Class Codes: H01S 5/026 Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers stabilisation of output H01S5/06

Abstract

Nanometer scale silicon-on-insulator (SOI) guided-wave optical components in the near infra-red employ an SOI platform for optical isolation, and single mode silicon strip etched into the buried oxide. A multi-layer core for the strip consistes of several 1-3 nanometer crystal silicon multiple quantum wells confined by wide bandgap epitaxial barriers. The MQW region of the strip employs intersubband or band-to-band photonic effects. Active strip microcavities use a photonic bandgap resonator of etched air cylinders, or two sets of etched slot Bragg grating reflectors. Many thousands of these components can be integrated on a Si chip.

Claims

1. A silicon-on-insulator single mode waveguide for transmitting optical waves in the near infra-red wavelength range comprising:

(a) a silicon light transmissive strip having a lower surface portion, a cross sectional height H of less than about 300 nanometers and wherein said lower surface portion has a cross sectional width of less than 1-5 H;

(b) a dielectric insulating layer having an upper surface portion underlying the lower surface portion of said light transmissive strip, and a lower surface portion;

(c) a silicon substrate having an upper surface portion underlying the lower surface portion of said dielectric insulating layer.

2. The waveguide of claim 1 wherein the height and width of said silicon light transmissive strip both equal about 0.2 times the wavelength of light in free space transmitted therethrough.

3. The waveguide of claim 2 wherein said dielectric insulating layer is selected from the group consisting of SiO₂, BeTeSe, gamma-Al₂ O₃, and CaF₂.

4. The waveguide of claim 3 wherein said dielectric insulating layer has a stairstep portion formed thereon and having the entire uppermost surface portion of said stairstep portion in contact with the lower surface portion of said silicon light transmissive strip.

5. The waveguide of claim 3 wherein said silicon light transmissive strip includes active multiple quantum wells with high barriers formed in a core portion thereof.

6. The waveguide of claim 2 wherein said dielectric insulating layer has a stairstep portion formed thereon and having the entire uppermost surface portion of said stairstep portion in contact with the lower surface portion of said silicon light transmissive strip.

7. The waveguide of claim 2 wherein said silicon light transmissive strip includes active multiple quantum wells with high barriers formed in a core portion thereof.

8. The waveguide of claim 2 wherein said silicon light transmissive strip includes a high Q microcavity formed therein.

9. The waveguide of claim 1 wherein said dielectric insulating layer is selected from the group consisting of SiO₂, BeTeSe, gamma-Al₂ O₃, and CaF₂.

10. The waveguide of claim 9 wherein said dielectric insulating layer has a stairstep portion formed thereon and having the entire uppermost surface portion of said stairstep portion in contact with the lower surface portion of said silicon light transmissive strip.

11. The waveguide of claim 9 wherein said silicon light transmissive strip includes active multiple quantum wells with high barriers formed in a core portion thereof.

12. The waveguide of claim 9 wherein said silicon light transmissive strip includes a high Q microcavity formed therein.

13. The waveguide of claim 1 wherein said dielectric insulating layer has a stairstep portion formed thereon and having the entire uppermost surface portion of said stairstep portion in contact with the lower surface portion of said silicon light transmissive strip.

14. The waveguide of claim 13 wherein said silicon light transmissive strip includes active multiple quantum wells with high barriers formed in a core portion thereof.

15. The waveguide of claim 13 wherein said silicon light transmissive strip includes a high Q microcavity formed therein.

16. The waveguide of claim 1 wherein said silicon light transmissive strip includes active electro-optic multiple quantum wells with high barriers formed in a core portion thereof.

17. The waveguide of claim 1 wherein said silicon light transmissive strip includes a high Q microcavity formed therein.

18. The waveguide of claim 1 wherein said dielectric insulating layer has a thickness of 0.5 microns or more.

19. A silicon-on-insulator single mode waveguide for transmitting optical waves in the near infra-red wavelength range comprising:

(a) a silicon light transmissive strip having a rectangular cross section, an upper and lower surface portion, a height H of less than 300 nanometers and a width of less than 1.5 H;

(b) a dielectric insulating layer having an upper surface portion in contact with the lower surface portion of said light transmissive strip, and a lower surface portion; and

(c) a silicon substrate having an upper surface portion in contact with the lower surface portion of said dielectric insulating layer.

20. The waveguide of claim 19 wherein the height and width of said silicon light transmissive strip both equal about 0.2 times the wavelength of light in free space transmitted therethrough.

21. The waveguide of claim 20 wherein said dielectric insulating layer is selected from the group consisting of SiO₂, BeTeSe, gamma-Al₂ O₃, and CaF₂.

22. The waveguide of claim 21 wherein said dielectric insulating layer has a stairstep portion formed thereon and having the entire uppermost surface portion of said stairstep portion in contact with the lower surface portion of said silicon light transmissive strip.

23. The waveguide of claim 21 wherein said silicon light transmissive strip includes active multiple quantum wells with high barriers formed in a core portion thereof.

24. The waveguide of claim 21 wherein said silicon light transmissive strip includes a high Q microcavity formed therein.

25. The waveguide of claim 20 wherein said dielectric insulating layer has a stairstep portion formed thereon and having the entire uppermost surface portion of said stairstep portion in contact with the lower surface portion of said silicon light transmissive strip.

26. The waveguide of claim 20 wherein said silicon light transmissive strip includes a high Q microcavity formed therein.

27. The waveguide of claim 20 wherein said silicon light transmissive strip includes active multiple quantum wells with high barriers formed in a core portion thereof.

28. The waveguide of claim 19 wherein said dielectric insulating layer is selected from the group consisting Of SiO₂, BeTeSe, gamma-Al₂ O₃, and CaF₂.

29. The waveguide of claim 28 wherein said dielectric insulating layer has a stairstep portion formed thereon and having the entire uppermost surface portion of said stairstep portion in contact with the lower surface portion of said silicon light transmissive strip.

30. The waveguide of claim 28 wherein said silicon light transmissive strip includes active multiple quantum wells with high barriers formed in a core portion thereof.

31. The waveguide of claim 28 wherein said silicon light transmissive strip includes a high Q microcavity formed therein.

32. The waveguide of claim 19 wherein said dielectric insulating layer has a stairstep portion formed thereon and having the entire uppermost surface portion of said stairstep portion in contact with the lower surface portion of said silicon light transmissive strip.

33. The waveguide of claim 32 wherein said silicon light transmissive strip includes active multiple quantum wells with high barriers formed in a core portion thereof.

34. The waveguide of claim 19 wherein said silicon light transmissive strip includes active electro-optic multiple quantum wells with high barriers formed in a core portion thereof.

35. The waveguide of claim 19 wherein said silicon light transmissive strip includes a high Q microcavity formed therein.

36. The waveguide of claim 19 wherein said dielectric insulating layer has a thickness of 0.5 microns or more.

37. A silicon-on-insulator single mode waveguide for transmitting optical waves in the near infra-red wavelength range comprising:

(a) a silicon light transmissive strip having a square cross section, the sides of said square cross section having a length of about 0.2 times the wavelength of light in free space transmitted therethrough;

(b) a dielectric insulating layer having an upper surface portion in contact with a lower surface portion of said light transmissive strip, and a lower surface portion; and

(c) a silicon substrate having an upper surface portion in contact with the lower surface portion of said dielectric insulating layer.

38. The waveguide of claim 37 wherein the sides of said square cross section are equal to about 250 nanometers.

39. The waveguide of claim 37 wherein said dielectric insulating layer has a thickness of 0.5 microns or more.

40. A silicon-on-insulator single mode waveguide for transmitting optical waves in the near infra-red wavelength range comprising:

(a) a crystal silicon light transmissive strip having a lower surface portion, a cross sectional height H of less than about 300 nanometers and wherein said lower surface portion has a cross sectional width of less than 1.5 H; and

(b) a dielectric insulating layer of single crystal bulk sapphire having an upper surface portion underlying the lower surface portion of said light transmissive strip.