Rotation-sensitive semiconductor ring laser device using the nonlinear Sagnac effect

Patent metadata

Field	Value
Publication number	US-9354062-B2
Application number	US-201313987911-A
Country	US
Kind code	B2
Filing date	Sep 16, 2013
Priority date	Sep 16, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

Method and apparatus embody a rotation sensor including one or more ring lasers designed to utilize a nonlinear Sagnac effect, a passive waveguide arrangement, and a photodetector arrangement to receive the outcoupled light and to detect rotation of the sensor; wherein these components are arranged into a monolithically integrated optoelectronic integrated circuit on a single substrate. The method and apparatus can include seeding a stable, rotation -insensitive, strong (driving) wave using a single-frequency edge emitting laser monolithically integrated on the same substrate.

First claim

What is claimed is:

1. A laser gyroscope rotation sensor comprising:
a ring laser designed to utilize a nonlinear Sagnac effect;
another laser arranged to interact with the ring laser to produce a nonlinear Sagnac effect;
a passive waveguide arranged to couple the light out from the ring laser;
a photodetector arranged to receive the light generated by the ring laser and to detect rotation of the sensor using the nonlinear Sagnac effect;
wherein the ring laser, the another laser the passive waveguide, and the photodetector are arranged into a monolithically integrated optoelectronic integrated circuit on a single substrate.

2. A laser gyroscope rotation sensor, comprising:
a first unidirectional ring laser arranged in a first ring arrangement designed to utilize a nonlinear Sagnac effect;
a second unidirectional ring laser arranged in a second ring arrangement designed to utilize a nonlinear Sagnac effect;
a three-port passive waveguide combiner arranged to combine the output light from the first and second unidirectional ring lasers into a single waveguide;
a first passive waveguide arranged to couple the light from the first ring arrangement to the three-port waveguide combiner;
a second passive waveguide arranged to couple the light from the second ring arrangement to the three-port waveguide combiner;
a third passive waveguide arranged to further guide the light generated by the first and second lasers by collecting it at the three-port waveguide combiner and mixing it together;
a photodetector arranged to receive the light generated by the first and the second ring arrangements and to detect rotation of the sensor using the nonlinear Sagnac effect;
wherein the first unidirectional ring laser, the second unidirectional ring laser, the three -port passive waveguide combiner, the first passive waveguide, the second passive waveguide, the third passive waveguide, and the photodetector are arranged into a monolithically integrated optoelectronic integrated circuit on a single substrate.

3. The rotation sensor according to claim 2 , further comprising a redirecting waveguide in each of the ring arrangements, strongly coupled to the waves propagating in the undesirable direction.

4. The rotation sensor according to claim 3 , wherein the redirecting waveguides are straight waveguides.

5. The rotation sensor according to claim 3 , wherein the redirecting waveguides are S-shaped.

6. The rotation sensor according to claim 2 , wherein the unidirectional ring lasers have a compound cavity structure effective to reduce the number of longitudinal modes in a large ring cavity and thereby to increase the power in the driving wave(s).

7. The rotation sensor according to claim 6 , wherein the compound-cavity unidirectional ring lasers are formed by connecting two or more rings together using three-port couplers.

8. The rotation sensor according to claim 6 , wherein the compound-cavity unidirectional ring lasers are formed by connecting two or more rings together through their evanescent fields.

9. The rotation sensor according to claim 2 , wherein the three-port passive waveguide combiner includes a Y-junction passive waveguide combiner.

10. The rotation sensor according to claim 2 , wherein the compound-cavity unidirectional ring lasers coupled by three-port couplers each include one or more Y-junction waveguide splitters and combiners.

11. The rotation sensor according to claim 2 , wherein the lasing light generated by the first laser propagates in a single direction in the first ring arrangement, and the lasing light generated by the second laser propagates in the opposite single direction in the second ring arrangement.

12. The rotation sensor according to claim 2 , further comprising one or more heater modules arranged to tune the first ring arrangement and the second ring arrangement to each other and to control modal content of compound cavity ring resonators.

13. The rotation sensor according to claim 2 , wherein the first passive waveguide forms a directional coupler with the first ring arrangement, and the second passive waveguide forms a directional coupler with the second ring arrangement.

14. The rotation sensor according to claim 2 , wherein the third passive waveguide leading the light from the ring lasers to the photodetector has a tapered end, and the photodetector facet is oriented at the Brewster angle with respect to the waveguide axis, in order to reduce or eliminate possible reflections back to the ring lasers.

15. The rotation sensor according to claim 2 , further comprising one or more monitoring photodetectors, arranged to monitor operation and signal passage in the sensor, with corresponding waveguides leading the light from the first and/or second ring arrangements to the monitoring photodetectors.

16. The rotation sensor according to claim 15 , wherein the waveguides leading the light from the ring lasers to the monitoring photodetectors form directional couplers with the first and second ring arrangements.

17. The rotation sensor according to claim 15 , wherein the waveguides leading the light from the ring lasers to the monitoring photodetectors have tapered ends, and the photodetector facets are oriented at the Brewster angle with respect to the waveguide axis, in order to reduce or eliminate possible reflections back to the ring lasers.

18. The rotation sensor according to claim 2 , wherein the signal from the third passive waveguide is directed out from the chip and collected outside the chip for further analysis.

19. The rotation sensor according to claim 2 , wherein the signals from the first and second passive waveguides are directed out from the chip and combined outside the chip for further analysis.

20. The rotation sensor according to claim 2 , wherein the photodetector is arranged to detect a beating signal produced by coupling the signals from the first ring arrangement and the second ring arrangement, said signals resulting from the nonlinear Sagnac effect produced by rotation of the sensor.

21. The rotation sensor according to claim 20 , wherein the beating signal is related to a slope sensitivity that is used to determine a rotation rate of the sensor.

22. A method of sensing rotation, comprising:
a) providing a laser gyroscope rotation sensor by:
providing a ring laser designed to utilize a nonlinear Sagnac effect;
providing another laser arranged to interact with the ring laser to produce a nonlinear Sagnac effect;
providing a passive waveguide arranged to couple the light out from the ring laser;
providing a photodetector arranged to receive the light generated by the ring laser and to detect rotation of the sensor using the nonlinear Sagnac effect;
wherein the ring lasers, the another laser, the passive waveguide, and the photodetector are arranged into a monolithically integrated optoelectronic integrated circuit on a single substrate, and
b) rotating the rotation sensor.

23. A method of sensing rotation, comprising:
a) providing a laser gyroscope rotation sensor by:
providing a first unidirectional ring laser arranged in a first ring arrangement designed to utilize a nonlinear Sagnac effect;
providing a second unidirectional ring laser arranged in a second ring arrangement designed to utilize a nonlinear Sagnac effect;
providing a three-port passive waveguide combiner arranged to combine the output light from the first and second unidirectional ring lasers into a single waveguide;
providing a firs

Assignees

• Osinski Marek A
• Eliseev Petr G
• Taylor Edward W
• Stc Unm

Inventors

• Osinski Marek A
• Eliseev Petr G
• Taylor Edward W

Classifications

• G02F1/3519

  of Sagnac type, i.e. nonlinear optical loop mirror [NOLM] · CPC title

• G01C19/66

  Ring laser gyrometers · CPC title

• G01C19/727 Primary

  using a passive ring resonator · CPC title

• H01S3/1028

  by controlling the temperature · CPC title

• H01S5/4068

  with lateral coupling by axially offset or by merging waveguides, e.g. Y-couplers · CPC title