Ring laser gyroscope with integrated polarization

Patent metadata

Field	Value
Publication number	US-9389080-B2
Application number	US-201414150348-A
Country	US
Kind code	B2
Filing date	Jan 8, 2014
Priority date	Jan 8, 2014
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A ring laser gyroscope comprises a laser block that defines an optical closed loop pathway configured to contain a lasing gas. A plurality of mirror structures are respectively mounted on the laser block, with each of the mirror structures having a respective reflective surface that is in optical communication with the optical closed loop pathway. A plurality of electrodes are coupled to the laser block, with the electrodes configured to generate a pair of counter-propagating laser beams from the lasing gas in the optical closed loop pathway. At least one optical sensor is coupled to one of the mirror structures, with the optical sensor in optical communication with the closed loop pathway. A polarizer is in optical communication with the optical sensor. The polarizer is configured to pass laser light having substantially one polarization mode to the optical sensor.

First claim

What is claimed is:

1. A ring laser gyroscope, comprising:
a laser block that defines an optical cavity having an optical closed loop pathway configured to contain a lasing gas;
a plurality of mirror structures respectively mounted on the laser block, each of the mirror structures having a respective reflective surface that is in optical communication with the optical closed loop pathway, wherein each of the mirror structures has a nonmagnetic construction;
a plurality of electrodes coupled to the laser block, the electrodes configured to generate a pair of counter-propagating laser beams from the lasing gas in the optical closed loop pathway;
at least one optical sensor coupled to one of the mirror structures, the optical sensor in optical communication with the optical closed loop pathway; and
a polarizer directly coupled to the optical sensor outside of the optical cavity, the polarizer configured to pass laser light having substantially one polarization mode to the optical sensor;
wherein the ring laser gyroscope is in a nonmagnetic configuration, and the optical sensor is configured to measure intensity of the laser light having substantially one polarization mode, which allows a length of the optical closed loop pathway to be adjusted.

2. The ring laser gyroscope of claim 1 , wherein the optical sensor comprises a photo detector device.

3. The ring laser gyroscope of claim 2 , wherein the photo detector device comprises a package that includes a package window that faces a photo detector die inside of the package.

4. The ring laser gyroscope of claim 3 , wherein the polarizer comprises a polarizing layer located inside of the package on an inner surface of the package window such that the laser light passes through the package window and then the polarizing layer prior to being incident on the photo detector die.

5. The ring laser gyroscope of claim 3 , wherein the polarizer comprises a polarizing layer located outside of the package on an outer surface of the package window such that the laser light passes through the polarizing layer and then the package window prior to being incident on the photo detector die.

6. The ring laser gyroscope of claim 3 , wherein the polarizer comprises a polarizing layer located inside of the package over the photo detector die and facing the package window such that the laser beam passes through the package window and then the polarizing layer prior to being incident on the photo detector die.

7. The ring laser gyroscope of claim 1 , further comprising a readout sensor coupled to one of the mirror structures.

8. The ring laser gyroscope of claim 7 , further comprising a polarizing layer coupled to the readout sensor such that laser light having substantially one polarization mode is incident on the readout sensor.

9. The ring laser gyroscope of claim 1 , wherein the polarizer comprises an s-polarization film that substantially passes s-polarized light.

10. The ring laser gyroscope of claim 1 , wherein the polarizer comprises a p-polarization film that substantially passes p-polarized light.

11. The ring laser gyroscope of claim 1 , wherein an odd number of mirror structures are mounted on the laser block.

12. The ring laser gyroscope of claim 1 , wherein the plurality of electrodes include a cathode mounted on a first side of the laser block, a first anode mounted on a second side of the laser block, and a second anode mounted on a third side of the laser block.

13. The ring laser gyroscope of claim 1 , wherein the plurality of electrodes include an anode mounted on a first side of the laser block, a first cathode mounted on a second side of the laser block, and a second cathode mounted on a third side of the laser block.

14. The ring laser gyroscope of claim 1 , wherein the plurality of electrodes are configured to apply an electrical potential through the lasing gas to create a gas plasma discharge region in the optical closed loop pathway to generate the counter-propagating laser beams.

15. The ring laser gyroscope of claim 1 , wherein the plurality of electrodes include a pair of electrodes mounted in opposing recesses on one side of the laser block adjacent to the optical closed loop pathway.

16. The ring laser gyroscope of claim 15 , wherein the pair of electrodes is configured to create a capacitive radio frequency discharge region of the lasing gas in the optical closed loop pathway to generate the counter-propagating laser beams.

17. A ring laser gyroscope, comprising:
a laser block having an optical cavity including a plurality of interconnected passages that define an optical closed loop pathway having a substantially triangular shape, the optical closed loop pathway configured to contain a lasing gas;
a first mirror structure, a second mirror structure, and a third mirror structure, each of the mirror structures respectively mounted at a corner of the laser block and having a respective reflective surface that is in optical communication with the optical closed loop pathway, the first and second mirror structures each including a mechanism that changes a position of the respective reflective surface to adjust the length of the optical closed loop pathway;
a plurality of electrodes coupled to the laser block, the electrodes configured to generate a pair of counter-propagating laser beams from the lasing gas in the optical closed loop pathway;
a photo detector device coupled to the third mirror structure and in optical communication with the optical closed loop pathway, wherein the reflective surface of the third mirror structure is partially optically transmissive to allow passage of a portion of the laser beams; and
a polarizing film directly coupled to the photo detector device outside of the optical cavity and configured to substantially pass s-polarized light from the portion of the laser beams to the photo detector device;
wherein the ring laser gyroscope is in a nonmagnetic configuration, and the photo detector device is configured to measure intensity of the s-polarized light, which allows a length of the optical closed loop pathway to be adjusted based on changes to the position of the respective reflective surface of the first or second mirror structures in response to the measured intensity of the s-polarized light.

18. The ring laser gyroscope of claim 17 , wherein the plurality of electrodes are configured to apply an electrical potential through the lasing gas to create a gas plasma discharge region in the optical closed loop pathway to generate the counter-propagating laser beams.

19. The ring laser gyroscope of claim 17 , wherein the pair of electrodes is configured to create a capacitive radio frequency discharge region of the lasing gas in the optical closed loop pathway to generate the counter-propagating laser beams.

20. The ring laser gyroscope of claim 17 , further comprising:
a readout sensor coupled to one of the mirror structures; and
a polarizing film coupled to the readout sensor, the polarizing film configured to pass laser light having substantially one polarization mode to the readout sensor.

Assignees

• Honeywell Int Inc

Inventors

• Schober Christina Marie
• Seiber Bruce A
• Thorland Rodney Harold
• Vescera James A

Classifications

• H01S3/097

  by gas discharge of a gas laser · CPC title

• H01S3/139

  by controlling the mutual position or the reflecting properties of the reflectors of the cavity {, e.g. by controlling the cavity length} · CPC title

• H01S3/0385

  Shape · CPC title

• H01S3/0835

  Gas ring lasers · CPC title

• H01S3/03

  of gas laser discharge tubes · CPC title