Free-space optically accessed acoustically modulated retro-reflector arrays

Patent metadata

Field	Value
Publication number	US-9377349-B2
Application number	US-201313974162-A
Country	US
Kind code	B2
Filing date	Aug 23, 2013
Priority date	Aug 23, 2013
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

Systems and techniques are provided for transmitting a light towards a plurality of acousto-optic retro reflectors, arranged as an array, that are configured to physically react to an acoustic signal. The physical reaction modulates the transmitted light which is reflected back towards a light detector and analyzed. The analysis may include detecting an acoustic signal source location and/or reconstructing the acoustic signal. A light scanner may be configured to transmit the light towards the plurality of acousto-optic retro reflectors in a predetermined, continuance, or dynamically determined sequence.

First claim

The invention claimed is:

1. A system comprising:
a plurality of acousto-optic retro reflectors, wherein each of the acousto-optic retro reflectors is configured to physically react in response to an acoustic signal;
a light scanner configured to sequentially transmit a first light signal towards each individual acousto-optic retro reflector in the plurality of acousto-optic retro reflectors;
a light detector configured to receive a second light signal emitted by the light scanner, wherein the second light signal is reflected by the plurality of acousto-optic retro reflectors; and
a processor configured to determine at least one property of the acoustic signal based upon the second light signal received by the light detector.

2. The system of claim 1 , wherein the plurality of acousto-optic retro reflectors are arranged as a one dimensional array.

3. The system of claim 1 , wherein the plurality of acousto-optic retro reflectors are arranged as a multi-dimensional array.

4. The system of claim 1 , wherein the plurality of acousto-optic retro reflectors are arranged as an end-fire array.

5. The system of claim 1 , wherein the plurality of acousto-optic retro reflectors are arranged as a broadside array.

6. The system of claim 1 , wherein the first light signal is a laser light.

7. The system of claim 6 , wherein the laser light is emitted from a device in a group consisting of a gas laser, a chemical laser, an excimer laser, a solid-state laser, a fiber laser, a photonic crystal laser, a semiconductor laser, a dye laser, a free electron laser, and a bio laser.

8. The system of claim 1 , wherein the plurality of acousto-optic retro reflectors are passive.

9. The system of claim 1 , wherein the determining at least one property of the acoustic signal comprises detecting an acoustic signal source location.

10. The system of claim 1 , wherein the determining at least one property of the acoustic signal comprises reconstructing the acoustic signal.

11. The system of claim 1 , wherein the light scanner is further configured to transmit a light signal towards, and receive a light signal from, an additional acousto-optic retro reflector based on the determining at least one property of the acoustic signal.

12. The system of claim 1 , wherein the light scanner is further configured to cease transmitting light towards, and receiving light from, a spare acousto-optic retro reflector based on the determining at least one property of the acoustic signal.

13. The system of claim 1 , wherein the light scanner and the light detector are a single unit.

14. The system of claim 1 , wherein the second light signal reflected by the plurality of acousto-optic retro reflectors is an acoustically modulated form of the first light signal emitted by the light scanner.

15. The system of claim 1 , wherein the sequence is predetermined.

16. The system of claim 15 , wherein the processor is further configured to determine at least one property of the acoustic signal based at least on the location of the plurality of acousto-optic retro reflectors and the predetermined sequence.

17. The system of claim 1 , wherein the sequence is a continuous scan.

18. The system of claim 17 , further configured to:
establish an array topology based on the second light signal received as a result of the continuous scan; and
determine at least one property of the acoustic signal based on array topology.

19. The system of claim 1 , wherein the sequence is determined dynamically.

20. The system of claim 19 , further configured to determine a sequence based on the light detector successfully receiving an acoustically modulated light signal from one or more of the plurality of acousto-optic retro reflectors, wherein the sequence incorporates at least the acousto-optic retro reflectors from which the light detector successfully received an acoustically modulated light signal.

21. The system of claim 20 , further configured to:
establish an array topology based on the location of the acousto-optic retro reflectors from which the light detector successfully received an acoustically modulated light signal; and
determine at least one property of the acoustic signal based on array topology.

22. The system of claim 1 , further configured to:
determine an array topology based on the plurality of acousto-optic retro reflectors; and
determine at least one property of the acoustic signal based on the array topology.

23. The system of claim 1 , wherein the light source is separated from the plurality of acousto-optic retro reflectors by free-space.

24. The system of claim 1 , wherein the light detector is separated from the plurality of acousto-optic retro reflectors by free-space.

25. The system of claim 1 , wherein the light scanner is configured to transmit the first light signal independent of the second light signal.

26. The system of claim 1 , wherein the light sensor is placed within a line of sight of the plurality of acousto-optic retro reflectors.

27. The system of claim 1 , wherein an acousto-optic retro reflector in the plurality of acousto-optic retro reflectors is selected from the group consisting of a corner cube reflector and a spherical reflector.

28. A method, comprising:
sequentially transmitting a light signal towards each individual acousto-optic retro reflector in a plurality of acousto-optic retro reflectors, wherein the plurality of acousto-optic retro reflectors is configured to physically react to an acoustic signal;
receiving a modulated form of at least one transmitted light signal resulting from the physical reaction of at least one corresponding reflector of the plurality of acousto-optic retro reflectors; and
determining at least one property of the acoustic signal based upon the modulated form of the at least one transmitted light signal.

29. The method of claim 28 , wherein the plurality of acousto-optic retro reflectors is arranged as a one dimensional array.

30. The method of claim 28 , wherein the plurality of acousto-optic retro reflectors is arranged as a multi-dimensional array.

31. The method of claim 28 , wherein the plurality of acousto-optic retro reflectors is arranged as an end-fire array.

32. The method of claim 28 , wherein the plurality of acousto-optic retro reflectors is arranged as a broadside array.

33. The method of claim 28 , wherein the plurality of acousto-optic retro reflectors is passive.

34. The method of claim 28 , wherein the determining at least one property of the received modulated form of the transmitted light signal comprises detecting an acoustic signal source location.

35. The method of claim 28 , wherein the determining at least one property of the received modulated form of the transmitted light signal comprises reconstructing the acoustic signal.

36. The method of claim 28 , wherein the light scanner and the light detector are a single unit.

Assignees

• Google Inc

Inventors

• Sleator Michael

Classifications

• G01H9/00 Primary

  Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means · CPC title