Variable optical power limiter

• US 20060159382A1
• Filed: 01/20/2005
• Published: 07/20/2006
• Est. Priority Date: 01/20/2005
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Rong, Haisheng
• Granted Patent: US 7,840,098 B2
• Time in Patent Office: Days
• US Class Current: 385/1
• CPC Class Codes: G02F 1/0156 using free carrier absorption
• CPC Class Codes: G02F 1/025 in an optical waveguide structure G02F1/017, G02F1/2257 take precedence
• CPC Class Codes: G02F 1/3526 using two-photon emission or absorption processes

Abstract

A variable optical power limiter is disclosed. An apparatus according to aspects of the present invention includes an optical waveguide disposed in semiconductor material. An optical beam is to be directed through the optical waveguide. The optical beam is to generate free carriers in the optical waveguide via two-photon absorption in response to an input power level of the optical beam. A diode structure is disposed in the optical waveguide. The diode structure is coupled to be biased to control free carrier lifetimes of the free carriers in the optical waveguide to set an output power of the optical beam to a clamped output power level in response to the bias of the diode structure.

Claims

1. An apparatus, comprising:

optical waveguide disposed in semiconductor material, an optical beam to be directed through the optical waveguide, the optical beam to generate free carriers in the optical waveguide via two-photon absorption in response to an input power level of the optical beam; and

a diode structure disposed in the optical waveguide, the diode structure coupled to be biased to control free carrier lifetimes of the free carriers in the optical waveguide to limit an output power of the optical beam to a clamped output power level in response to the bias of the diode structure.

2. The apparatus of claim 1 further comprising a voltage source coupled to a P region and an N region of the diode structure.

3. The apparatus of claim 2 wherein the voltage source is a variable voltage source to vary the clamped output power level.

4. The apparatus of claim 1 wherein the diode structure comprises a PIN diode disposed in the optical waveguide.

5. The apparatus of claim 1 wherein the diode structure comprises:

a P region disposed on a lateral side of the optical waveguide; and

an N region disposed on an opposite lateral side of the optical waveguide.

6. The apparatus of claim 1 wherein the semiconductor material comprises silicon.

7. The apparatus of claim 1 wherein the optical waveguide comprises a silicon rib waveguide disposed in the semiconductor material.

8. The apparatus of claim 1 wherein the diode structure is coupled to be biased to sweep out the free carriers from the optical waveguide generated in response to the two-photon absorption occurring in the optical waveguide in response to the optical beam.

9. The apparatus of claim 1 wherein the diode structure is coupled to be variably reversed biased.

10-16. -16. (canceled)

17. A system, comprising:

optical waveguide disposed in semiconductor material, an optical beam to be directed through the optical waveguide, the optical beam to generate free carriers in the optical waveguide via two-photon absorption in response to an input power level of the optical beam;

a diode structure disposed in the optical waveguide, the diode structure coupled to be biased to control free carrier lifetimes of the free carriers in the optical waveguide to limit an output power of the optical beam to a clamped output power level in response to the bias of the diode structure;

an optical fiber optically coupled to receive the optical beam from the optical waveguide; and

an optical receiver optically coupled to receive the optical beam from the optical waveguide through the optical fiber.

18. The system of claim 17 further comprising a variable voltage source coupled to the diode structure to control a reverse bias of the diode structure to vary the clamped output power level.

19. The system of claim 17 wherein the optical beam is one of a plurality of optical beams and the optical receiver is one of a plurality of optical receivers, each of which is optically coupled to receive a respective one of the plurality of optical beams, wherein each of the plurality of optical beams received by the optical receivers has a power level equalized to the clamped output power level.

20. The system of claim 17 wherein each of the plurality of optical beams corresponds to a unique channel of an optical communication system.