Closed loop operation of broadband resonator optical gyroscope using sawtooth phase modulations

Patent metadata

Field	Value
Publication number	US-12467752-B2
Application number	US-202318341281-A
Country	US
Kind code	B2
Filing date	Jun 26, 2023
Priority date	Jun 26, 2023
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

Various examples of a closed-loop optical gyroscope are disclosed. The closed-loop optical gyroscope includes a broadband light source configured to generate broadband optical signal(s). The broadband optical signal(s) propagate in an optical resonator and are coupled in and out of the optical resonator by optical couplers. A phase modulator applies phase modulation to the optical signal(s) based on a sawtooth modulation signal. The optical signal(s) repropagate in the optical resonator in a different direction. The optical signal(s) are then received and analyzed to determine parameter(s) of the phase modulator. One or more processors configure the phase modulator based on the determined parameter(s).

First claim

What is claimed is:

1 . A closed-loop optical gyroscope, comprising:
a broadband light source configured to generate an optical signal having a broadband frequency range; a first optical coupler of an optical resonator coupled to the broadband light source and configured to couple the optical signal into the optical resonator, wherein the optical signal propagates in a first direction through the optical resonator; a second optical coupler of the optical resonator and coupled to the first optical coupler, wherein the second optical coupler is configured to couple the optical signal out of the optical resonator; a phase modulator coupled to the second optical coupler, wherein the phase modulator is configured to generate a phase-modulated optical signal from the optical signal based on a sawtooth modulation signal, wherein the phase modulator is configured to reduce an amplitude of the sawtooth modulation signal while maintaining a slope of the sawtooth modulation signal; wherein the second optical coupler is configured to provide the phase-modulated optical signal back into the optical resonator, wherein the phase-modulated optical signal propagates in a second direction different from the first direction through the optical resonator to the first optical coupler, wherein the first optical coupler is configured to couple the phase-modulated optical signal out of the optical resonator, and a control servo coupled to the first optical coupler and the phase modulator, wherein the control servo is configured to receive a signal corresponding to the phase-modulated optical signal from the first optical coupler and configured to adjust at least one parameter of the phase modulator based on the received signal.

2 . The closed-loop optical gyroscope of claim 1 , wherein the control servo is configured to determine a power of the signal corresponding to the phase-modulated optical signal, wherein the control servo is configured to adjust the at least one parameter of the phase modulator based on the power.

3 . The closed-loop optical gyroscope of claim 1 , wherein the control servo is configured to send at least one control signal including the adjusted at least one parameter to the phase modulator, wherein the phase modulator is configured to modulate the optical signal based on the at least one control signal.

4 . The closed-loop optical gyroscope of claim 1 , wherein the adjusted at least one parameter includes a slope adjustment of the sawtooth modulation signal.

5 . The closed-loop optical gyroscope of claim 4 , wherein the phase modulator is configured to generate an adjusted phase-modulation signal based on the slope adjustment.

6 . The closed-loop optical gyroscope of claim 1 , comprising at least one polarizer coupled to an optical path of the optical resonator, wherein the at least one polarizer acts as a filter to pass the optical signal at a first polarization state and attenuates the optical signal at another polarization state.

7 . A system, comprising:
a broadband light source configured to generate an optical signal having a broadband frequency range; a first optical coupler of an optical resonator coupled to the broadband light source and configured to couple the optical signal into the optical resonator, wherein the optical signal propagates in a first direction through the optical resonator; a second optical coupler of the optical resonator and coupled to the first optical coupler, wherein the second optical coupler is configured to couple the optical signal out of the optical resonator; a phase modulator coupled to the second optical coupler, wherein the phase modulator is configured to generate a phase-modulated optical signal from the optical signal based on a sawtooth modulation signal, wherein the phase modulator is configured to reduce an amplitude of the sawtooth modulation signal while maintaining a slope of the sawtooth modulation signal; wherein the second optical coupler is configured to provide the phase-modulated optical signal back into the optical resonator, wherein the phase-modulated optical signal propagates in a second direction different from the first direction through the optical resonator to the first optical coupler, wherein the first optical coupler is configured to couple the phase-modulated optical signal out of the optical resonator, and at least one processor coupled to the first optical coupler and the phase modulator, wherein the at least one processor is configured to receive a signal corresponding to the phase-modulated optical signal from the first optical coupler and configured to adjust at least one parameter of the phase modulator based on the received signal.

8 . The system of claim 7 , wherein the at least one processor is configured to determine a power of the signal corresponding to the phase-modulated optical signal, wherein the at least one processor is configured to adjust the at least one parameter of the phase modulator based on the power.

9 . The system of claim 7 , wherein the at least one processor is configured to send at least one control signal including the adjusted at least one parameter to the phase modulator, wherein the phase modulator is configured to modulate the optical signal based on the at least one control signal.

10 . The system of claim 7 , wherein the adjusted at least one parameter includes a slope adjustment of the sawtooth modulation signal.

11 . The system of claim 10 , wherein the phase modulator is configured to generate an adjusted phase-modulation signal based on the slope adjustment.

12 . The system of claim 7 , comprising at least one polarizer coupled to an optical path of the optical resonator, wherein the at least one polarizer acts as a filter to pass the optical signal at a first polarization state and attenuates another polarization state of the optical resonator.

13 . A method for operating a closed-loop optical gyroscope, comprising:
generating an optical signal having a broadband frequency range; coupling, via a first optical coupler, the optical signal into an optical resonator, wherein the optical signal propagates in a first direction through the optical resonator; coupling, via a second optical coupler, the optical signal out of the optical resonator; modulating, via a phase modulator, the optical signal with a sawtooth modulation signal to generate a phase-modulated optical signal, wherein the phase modulator is configured to reduce an amplitude of the sawtooth modulation signal while maintaining a slope of the sawtooth modulation signal; coupling, via the second optical coupler, the phase-modulated optical signal back into the optical resonator, wherein the phase-modulated optical signal propagates in a second direction through the optical resonator different from the first direction; coupling, via the first optical coupler, the phase-modulated signal out of the optical resonator; receiving, at a control servo, a signal corresponding to the phase-modulated optical signal; and adjusting at least one parameter of the phase modulator based on the received signal.

14 . The method of claim 13 , comprising determining a power of the signal corresponding to the phase-modulated optical signal; and adjusting the at least one parameter of the phase modulator based on the power.

15 . The method of claim 13 , comprising:
adjusting a slope of the sawtooth modulation signal; and generating an adjusted phase modulation signal based on the adjusted slope of the sawtooth modulation signal.

16 . The method of claim 13 , comprising:
filtering, via at least one po

Assignees

• Honeywell Int Inc

Inventors

• Qiu Tiequn
• Wu Jianfeng
• Puckett Matthew Wade
• Tin Steven
• Sanders Glen A

Classifications

• G02F2203/15

  involving resonance effects, e.g. resonantly enhanced interaction · CPC title

• G02F1/0121

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

• G01C19/721 Primary

  Details, e.g. optical or electronical details · CPC title

• G01C19/722 Primary

  of the mechanical construction · CPC title

• G01C19/725 Primary

  using nxn optical couplers, e.g. 3x3 couplers · CPC title