Optical sample and hold system and method

• US 10,069,619 B1
• Filed: 03/06/2013
• Issued: 09/04/2018
• Est. Priority Date: 08/05/2011
• Status: Expired due to Fees

• Current Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Original Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Inventors: Zanoni, Raymond, Jepsen, Kim S., Laliberte, Mark A., King, Oliver S.
• Primary Examiner(s): Vanderpuye, Ken N
• Assistant Examiner(s): Lambert, David
• Application Number:
  US13/787,202
• Time in Patent Office: 2,008 Days
• Field of Search: None
• CPC Class Codes: G02F 7/00 Optical analogue/digital converters
• CPC Class Codes: H03M 1/1245 Details of sampling arrangements or methods
• CPC Class Codes: H04B 2210/006 Devices for generating or processing an RF signal by optical means
• CPC Class Codes: H04L 7/0075 with photonic or optical means

Abstract

A method of performing optical serial-to-parallel conversion of an optical signal includes performing phase modulation of the optical pulse stream and outputting a phase-modulated optical signal as a result thereof. The method also includes performing optical switching of the phase-modulated optical signal by optical switches connected to each other in a series relationship on a signal path. The method further includes performing optical switching of a reference optical clock signal by optical switches connected to each other in a series relationship on a reference path. The method also includes performing, by I/Q demodulators, I/Q demodulation of the optically switched phase-modulated optical signal respectively output by one of the optical switches on the signal path at timings corresponding to the optically switched reference optical clock signal respectively output by one of the optical switches on the reference path, in which the I/Q demodulators respectively output I and Q demodulated signals as a result thereof. The method further includes performing, by pairs of gated photodetectors respectively connected to the I/Q demodulators, photodetection of the I and Q demodulated signals respectively output of the I/Q demodulators.

Claims

1. A photonic processor, comprising:

a phase modulator configured to receive a first electronic signal and an optical clock signal, the optical clock signal received from an optical clock circuit on a first path, and to provide a phase modulated optical pulse signal;

at least one optical demodulator respectively configured to receive the phase modulated optical pulse signal on a signal path and the optical clock signal on a reference path from the optical clock circuit, wherein the at least one optical demodulator is configured to perform demodulation of the phase modulated optical pulse signal at timings corresponding to the optical clock signal received from the optical clock circuit on the reference path to provide an optical I demodulated signal on a first output of the optical demodulator and an optical Q demodulated signal on a second output of the optical demodulator; and

at least one photo converter configured to receive at least one of the optical I demodulated signal and the optical Q demodulated signal and to provide a second electronic signal corresponding to the at least one of the optical I demodulated signal and the optical Q demodulated signal, each photo converter of the at least one photo converter including an optical gate configured to hold the at least one of the optical I demodulated signal and the optical Q demodulated signal at timings corresponding to the optical clock signal and a photodetector configured to provide the second electronic signal, the optical gate between the at least one optical demodulator and the photodetector, wherein sampling is performed in the optical domain.

2. The photonic processor according to claim 1, further comprising:

a clock generator configured to provide an electronic clock signal to the photo converter.

3. The photonic processor according to claim 2, wherein the photonic processor operates as a sample-and-hold circuit wherein the optical clock signal and phase modulator perform a sample function of the sample-and-hold circuit and the photo converter performs a hold function of the sample-and-hold circuit.

4. The photonic processor according to claim 1, wherein the signal path and the reference path are separate paths that do not directly intersect or directly connect with each other.

5. The photonic processor according to claim 1, wherein the optical clock circuit is a mode locked laser or a coupled opto-electronic oscillator.

6. A method of multi-dimensional quantization, the method comprising:

performing phase modulation and providing a phase-modulated optical pulse signal based on an optical clock signal received from an optical clock circuit;

performing by at least one optical demodulator, demodulation of the phase-modulated optical pulse signal at timings corresponding to the optical clock signal received on a reference path from the optical clock circuit to provide an optical I demodulated signal and an optical Q demodulated signal;

receiving, by a first photo converter, the optical I demodulated signal;

receiving, by a second photo converter, the optical Q demodulated signal;

converting, by a first photodetector of the first photo converter, the optical I demodulated signal to a first electronic signal;

converting, by a second photodetector of the second photo converter, the optical Q demodulated signal to a second electronic signal;

holding, by a first optical gate of the first photo converter, the optical I demodulated signal at timings corresponding to the optical clock signal, the first optical gate between the at least one optical demodulator and the first photodetector; and

holding, by a second optical gate of the second photo converter, the optical Q demodulated signal at timings corresponding to the optical clock signal, the second optical gate between the at least one optical demodulator and the second photodetector.

7. The method according to claim 6, wherein a sample-and-hold function is performed using an optical clock signal and a phase modulator to perform a sample function and the plurality of pairs of gated photodetectors to perform a hold function.

8. The method according to claim 6, wherein a signal path receives the phase-modulated optical pulse signal and the reference path receives the optical clock signal, the signal path and the reference path are separate paths that do not directly intersect or directly connect with each other.

9. The method according to claim 6, wherein the phase modulation uses a radio frequency electronic signal and a reference optical clock signal.

10. A photonic processor, comprising:

a phase modulator configured to receive an electronic radio frequency signal and an optical clock signal, the optical clock signal received from an optical clock circuit on a first path, and to provide a phase-modulated optical signal;

a demodulator configured to receive the phase-modulated optical signal output by the phase modulator on a signal path, to receive the optical clock signal on a reference path from the optical clock circuit, and to perform demodulation of the phase-modulated optical signal at timings corresponding to the optical clock signal received on the reference path from the optical clock circuit, wherein the demodulator provides an optical I demodulated signal and an optical Q demodulated signal; and

first and second photodetectors coupled to the demodulator and configured to receive respectively the optical I demodulated signal and the optical Q demodulated signal, each photodetector comprising (1) an optical gate configured to hold the respective optical I demodulated signal or optical Q demodulated signal at timings corresponding to the optical clock signal, and (2) a photodetector device configured to provide an electronic demodulated signal corresponding to the respective optical I demodulated signal or optical Q demodulated signal, each optical gate being disposed between the demodulator and the corresponding photodetector device.

11. The photonic processor according to claim 10, further comprising:

first and second electronic quantizers coupled to the first and second photodetectors, respectively, and configured to perform electronic quantization of each respective electronic demodulated signal as first and second digital signals.

12. The photonic processor according to claim 10, further comprising:

an optical clock configured to output the optical clock signal to the phase modulator and to the reference path, wherein the phase modulator performs phase modulation of the phase-modulated optical signal at timings corresponding to the optical clock signal.

13. The photonic processor according to claim 10, wherein the photonic processor operates as a sample-and-hold circuit, wherein the optical clock signal and phase modulator perform a sample function of the sample-and-hold circuit and the photodetectors perform a hold function of the sample-and-hold circuit.

14. The photonic processor according to claim 10, further comprising:

a plurality of optical switches provided on the reference path and the signal path;

additional demodulators configured to receive the phase-modulated optical signal output by a respective optical switch on the signal path, and to perform demodulation of the phase-modulated optical signal in response to the optical clock signal received from a respective optical switch on the reference path.

15. The photonic processor according to claim 14, further comprising:

additional first and second photodetectors respectively coupled to the additional demodulators.