Devices and techniques for integrated optical data communication

• US 9,768,881 B2
• Filed: 03/15/2013
• Issued: 09/19/2017
• Est. Priority Date: 11/29/2012
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Georgas, Michael Stephen, Orcutt, Jason Scott, Stojanovic, Vladimir Marko
• Primary Examiner(s): Leung, Danny
• Application Number:
  US14/648,002
• Publication Number:
  US 20150311982A1
• Time in Patent Office: 1,649 Days
• CPC Class Codes: H04B 10/25891 Transmission components H04B10/40 takes precedence
• CPC Class Codes: H04B 10/60 Receivers
• CPC Class Codes: H04B 10/697 Arrangements for reducing noise and distortion

Abstract

Devices and techniques for integrated optical data communication. An optical receiver may include a photodetector and a differential amplifier. The photodetector is coupled to an optical waveguide. The optical waveguide is configured to provide an optical signal encoding data. A first terminal of the differential amplifier is coupled to receive a photodetection signal from the photodetector. A second terminal of the differential amplifier is coupled to receive, from a noise measurement unit, a reference signal representing a noise component of the photodetection signal. The differential amplifier is configured to provide an amplifier signal encoding at least some of the data.

Claims

1. An optical receiver, comprising:

a photodetection circuit coupled to an optical waveguide, the optical waveguide being configured to provide an optical signal; and

an amplification circuit, including;

a first amplifier configured to provide a first amplifier signal based on a first photodetection signal provided by the photodetection circuit, the first photodetection signal corresponding to a first portion of the optical signal, the first amplifier signal having a first data rate, and

a second amplifier configured to provide a second amplifier signal based on a second photodetection signal provided by the photodetection circuit, the second photodetection signal corresponding to a second portion of the optical signal, the second amplifier signal having a second data rate,

wherein the amplification circuit is configured to provide an electrical data signal by combining the first and second amplifier signals, the electrical data signal having a third data rate that is greater than each of the first and second data rates.

2. The optical receiver of claim 1, wherein:

the third data rate is approximately a sum of the first data rate and the second data rate.

3. The optical receiver of claim 1, wherein:

the first amplifier signal encodes a first bit and the second amplifier signal encodes and second bit, and when the second bit has a first bit value, a next bit to be encoded in the electrical data signal is provided by the first amplifier, and

when the second bit has a second bit value, the next bit to be encoded in the electrical data signal is provided by the second amplifier.

4. The optical receiver of claim 1, wherein the first amplifier and the second amplifier are configured to perform decision-feedback equalization.

5. The optical receiver of claim 1, wherein the first amplifier is an integrating amplifier.

6. The optical receiver of claim 1, wherein the photodetection circuit, the optical waveguide, and the amplification circuit are monolithically integrated on a semiconductor substrate.

7. The optical receiver of claim 1, wherein the photodetection circuit includes a photodetector configured to convert the first portion of the optical signal into the first photodetection signal, and to convert the second portion of the optical signal into the second photodetection signal.

8. The optical receiver of claim 7, wherein the photodetector is a photodiode.

9. The optical receiver of claim 1, wherein the photodetection circuit includes:

a first photodetector configured to convert the first portion of the optical signal into the first photodetection signal, and

a second photodetector configured to convert the second portion of the optical signal into the second photodetection signal.

10. The optical receiver of claim 9, wherein the first and second photodetectors are coupled to the optical waveguide.

11. The optical receiver of claim 9, wherein:

the first photodetector is coupled to a first branch of the optical waveguide,

the second photodetector is coupled to a second branch of the optical waveguide, and

the first and second branches of the optical waveguide are configured to provide, respectively, the first and second portions of the optical signal.

12. The optical receiver of claim 9, wherein the first photodetector is a photodiode.

13. The optical receiver of claim 1, wherein the photodetection circuit is configured to convert the first portion of the optical signal into the first photodetection signal, and to convert the second portion of the optical signal into the second photodetection signal.

14. A method comprising:

obtaining a first electrical signal and a second electrical signal, the first electrical signal corresponding to a first portion of the optical signal, the second electrical signal corresponding to a second portion of the optical signal;

with a first amplifier, providing a first amplifier signal based on the first electrical signal, the first amplifier signal having a first data rate;

with a second amplifier, providing a second amplifier signal based on the second electrical signal, the second amplifier signal having a second data rate; and

providing a data signal including the first amplifier signal and the second amplifier signal the data signal having a third data rate that is greater than each of the first and second data rates.

15. The method of claim 14, wherein obtaining the first electrical signal comprises converting the first portion of the optical signal into the first electrical signal.

16. The method of claim 14, wherein:

providing the data signal comprises providing the data signal including the first and second amplifier signals, and

the third data rate is approximately a sum of the first and second data rates.

17. The method of claim 14, wherein providing the data signal comprises:

in a case where a most recently encoded bit of the data signal has a first bit value, providing the data signal including the first amplifier signal, and

in a case where the most recently encoded bit of the data signal has a second bit value, providing the data signal including the second amplifier signal.

18. The method of claim 14, further comprising performing decision-feedback equalization with the first and second amplifiers.

19. The method of claim 14, wherein the first amplifier is a clocked amplifier.

20. The method of claim 14, wherein the photodetection circuit, the optical waveguide, and the first and second amplifiers are monolithically integrated on a semiconductor substrate.