System and method to produce tunable synthesized optical frequency

Patent metadata

Field	Value
Publication number	US-9647408-B2
Application number	US-201414531010-A
Country	US
Kind code	B2
Filing date	Nov 3, 2014
Priority date	Nov 3, 2014
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A control circuit for generating an optical output at a target frequency using a single-frequency laser is provided. The control circuit includes a micro-ring resonator configured to generate a frequency comb of a plurality of comb frequencies based on a source frequency, a carrier-envelope offset interferometer configured to determine a carrier-envelope offset frequency of the frequency comb, a tunable filter configured to select a subset of comb frequencies of the frequency comb based on the target frequency, and a spectrometer configured to resolve ambiguities in overlap between the subset of comb frequencies and the frequency comb, and refine the subset of comb frequencies to a single comb frequency for output.

First claim

What is claimed is:

1. A synthesizer system for generating an optical output at a target frequency, comprising:
a micro-ring resonator configured to generate a frequency comb of a plurality of comb frequencies based on a source frequency;
a carrier-envelope offset interferometer configured to determine a carrier-envelope offset frequency of the frequency comb;
a tunable filter configured to select a subset of comb frequencies of the frequency comb based on the target frequency; and
a spectrometer configured to select a single comb frequency for output based on the subset of comb frequencies.

2. The synthesizer system of claim 1 , wherein the micro-ring resonator is configured to adjust the frequency comb based at least partially on the carrier-envelope offset frequency and the target frequency.

3. The synthesizer system of claim 1 , wherein the carrier-envelope offset interferometer is configured to determine the carrier-envelope offset frequency based on a self-referencing scheme.

4. The synthesizer system of claim 1 , wherein a frequency value corresponding to an overlap between the subset of comb frequencies and the frequency comb is unambiguously determined at least partially by the spectrometer and adjustments made to a center frequency of the tunable filter.

5. The synthesizer system of claim 1 , wherein the source frequency is generated by a single-frequency laser and the target frequency corresponds to a microwave reference input signal.

6. The synthesizer system of claim 1 , wherein each of the micro-ring resonator, the carrier-envelope offset interferometer, and the tunable filter is disposed on a photonic substrate, and each of the micro-ring resonator, the carrier-envelope offset interferometer, and the tunable filter is operated at least in part by a corresponding servo disposed on an electronic substrate.

7. The synthesizer system of claim 6 , wherein the electronic substrate includes at least a laser servo, a resonator servo, a carrier-envelope offset servo, a filter servo, and a controller configured to operate each of the laser servo, the resonator servo, the carrier-envelope offset servo, and the filter servo.

8. A controller for generating an optical output at a target frequency using a single-frequency laser and a tunable filter, comprising:
a laser module configured to generate a source frequency based at least partially on the target frequency;
a resonator module configured to generate a frequency comb of a plurality of comb frequencies based on the source frequency;
a carrier-envelope offset module configured to determine a carrier-envelop offset frequency of the frequency comb; and
a filter module operatively coupled to a spectrometer configured to select one of the comb frequencies of the frequency comb for output based on the target frequency.

9. The controller of claim 8 , wherein the laser module is operatively coupled to the single-frequency laser, the resonator module is operatively coupled to a micro-ring resonator, the carrier-envelope offset module is operatively coupled to a carrier-envelope offset interferometer, the filter module is operatively coupled to the tunable filter.

10. The controller of claim 9 , wherein the laser module operates the single-frequency laser via a laser servo, the resonator module operates the micro-ring resonator via a resonator servo, the carrier-envelope offset module operates the carrier-envelope offset interferometer via a carrier-envelope offset servo, and the filter module operates the tunable filter via a filter servo.

11. The controller of claim 8 , wherein the resonator module is configured to adjust the frequency comb based at least partially on the carrier-envelope offset frequency and the target frequency.

12. The controller of claim 8 , wherein the carrier-envelope offset module is configured to determine the carrier-envelope offset frequency based on a self-referencing scheme.

13. The controller of claim 8 , wherein the filter module is configured to adjust a center frequency of the tunable filter so as to output one of the comb frequencies of the frequency comb corresponding to the target frequency.

14. The controller of claim 8 , wherein the target frequency corresponds to a microwave reference input signal.

15. A controller-implemented method of generating an optical output at a target frequency using a single-frequency laser and a tunable filter, comprising:
operating the single-frequency laser to generate a source frequency based at least partially on the target frequency;
generating a frequency comb of a plurality of comb frequencies based on the source frequency;
determining a carrier-envelope offset frequency based on the frequency comb; and
adjusting a center frequency of the tunable filter using an integrated spectrometer so as to output one of the comb frequencies of the frequency comb corresponding to the target frequency.

16. The controller-implemented method of claim 15 , wherein the frequency comb is adjusted based at least partially on the source frequency.

17. The controller-implemented method of claim 15 , wherein the frequency comb is adjusted based at least partially on the carrier-envelope offset frequency.

18. The controller-implemented method of claim 15 , wherein the frequency comb is adjusted based at least partially on measurements made by the integrated spectrometer.

19. The controller-implemented method of claim 15 , wherein the frequency comb is generated using a micro-ring resonator.

20. The controller-implemented method of claim 15 , wherein the carrier-envelope offset frequency is determined based on a self-referencing scheme.

Assignees

• Boeing Co

Inventors

• Lowell John R

Classifications

• H01S3/005

  Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping (shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B) · CPC title

• H01S3/1305

  Feedback control systems · CPC title

• H01S3/1307

  Stabilisation of the phase · CPC title

• G02F1/0121

  Operation of devices; Circuit arrangements, not otherwise provided for in this subclass · CPC title

• H01S3/0078 Primary

  Frequency filtering · CPC title