ELECTRO-OPTIC MODULATION

• US 20100266232A1
• Filed: 07/06/2010
• Published: 10/21/2010
• Est. Priority Date: 03/04/2005
• Status: Abandoned Application

• Current Assignee: Cornell Research Foundation Incorporated (Cornell University)
• Original Assignee: Cornell Research Foundation Incorporated (Cornell University)
• Inventors: Xu, Qianfan, Lipson, Michal, Schmidt, Bradley, Pradhan, Sameer
• Application Number:
  US12/831,013
• Publication Number:
  US 20100266232A1
• Time in Patent Office: Days
• US Class Current: 385/1
• CPC Class Codes: G02F 1/0152 using free carrier effects, e.g. plasma effect
• CPC Class Codes: G02F 1/025 in an optical waveguide structure G02F1/017, G02F1/2257 take precedence
• CPC Class Codes: G02F 2203/15 involving resonance effects, e.g. resonantly enhanced interaction

Abstract

A silicon electro-optic waveguide modulator is formed using a metal-oxide-semiconductor (MOS) configuration. Various embodiments are described using different modes of operation of the MOS diode and gate oxide thicknesses. In one example, a high-speed submicron waveguide active device is formed using silicon-on-insulator. A micro-ring resonator intensity-modulator exhibits switching times on the order of tens of pS with modulation depth of 73% with a bias voltage of 5 volts.

Claims

1. A method comprising:

providing light to a waveguide optically coupled to an optical resonator;

modulating the light in the waveguide by varying the optical coupling of the optical resonator to the waveguide.

2. The method of the claim 1 wherein the optical coupling is varied by changing a free carrier concentration in the optical resonator to vary the refractive index of the optical resonator.

3. The method of claim 1 wherein the optical resonator is a ring resonator.

4. The method of claim 1 wherein the optical resonator is a Fabry-Perot resonator.

5. The method of claim 1 wherein the optical resonator is an optical cavity.

6. The method of claim 1 and further comprising providing a p doped region and an n doped region adjacent to the optical resonator.

7. The method of claim 6 wherein the doped regions are heavily doped.

8. The method of claim 7 wherein the heavily doped regions form a p-i-n diode about the optical resonator.

9. The method of claim 1 wherein the free carrier concentration is changed by at least one of injection, accumulation, depletion and inversion of carriers.

10. The method of claim 2 wherein the carrier concentration is changed by a p-i-n diode.

11. The method of claim 2 wherein the carrier concentration is changed by metal-oxide-semiconductor field-effect-transistor.

12. A method comprising:

providing light to a optical ring resonator;

modulating the light in the optical ring resonator by changing its refractive index.

13. The method of claim 12 wherein the refractive index is changed by varying a free carrier concentration in the optical ring resonator.

14. The method of claim 12 where the light is provided to the optical ring resonator by an optically coupled waveguide.

15. The method of claim 12 and further comprising providing a p doped region and an n doped region adjacent to the optical ring resonator.

16. The method of claim 15 wherein the doped regions are heavily doped.

17. The method of claim 16 wherein the heavily doped regions form a p-i-n diode about the optical ring resonator.

18. The method of claim 12 wherein the free carrier concentration is changed by at least one of injection, accumulation, depletion and inversion of carriers.

19. The method of claim 18 wherein the carrier concentration is changed by metal-oxide-semiconductor field-effect-transistor about the optical ring resonator.

20. A method comprising:

providing light to a waveguide;

modulating the light in the waveguide by changing the refractive index of an optical resonator coupled to the waveguide.

21. The method of claim 20 wherein the refractive index is changed by changing the free carrier concentration in the optical resonator.

22. The method of claim 21 wherein varying the refractive index changes optical coupling of the optical waveguide to the waveguide.