Device, system, and method for controlling the focus of a laser to induce plasmas that emit signals with high directivity

Patent metadata

Field	Value
Publication number	US-11035925-B2
Application number	US-201816058758-A
Country	US
Kind code	B2
Filing date	Aug 8, 2018
Priority date	Aug 8, 2018
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

A focus controlling component is configured to control a focus of a laser beam that passes through water and induces plasmas that emit signals. The focus of the laser beam is controlled such that the signals emitted by the induced plasmas interfere to form a combined signal that propagates in a desired direction.

First claim

What is claimed is:

1. A device, comprising:
a focus controlling component configured to control a focus of a laser beam that passes through water and induces plasmas that emit signals, wherein the focus of the laser beam is controlled such that the signals emitted by the induced plasmas interfere to form a combined signal that propagates in a desired direction.

2. The device of claim 1 , wherein the focus controlling component causes the focus of the laser beam to have a focal pattern that is three dimensional with multiple foci.

3. The device of claim 2 , wherein the focus controlling component is configured to adjust the focal pattern of the laser beam to adjust the desired direction of propagation of the combined signal.

4. The device of claim 1 , wherein the focus controlling component controls the focus of the laser beam such that the induced plasmas are shaped such that the emitted signals interfere to form the combined signal that propagates in the desired direction.

5. The device of claim 1 , wherein the focus controlling component is a phase mask.

6. The device of claim 5 , wherein the phase mask includes a computer controlled spatial light modulator.

7. The device of claim 5 , wherein the phase mask includes multiple diffraction gratings.

8. The device of claim 7 , wherein the multiple diffraction gratings control the focus of the laser beam such that the focal pattern has a fractal shape.

9. The device of claim 5 , wherein the phase mask includes multiple liquid crystal spatial light modulators.

10. The device of claim 1 , wherein the focus controlling component includes a computer-controlled beam rasterizer.

11. A system, comprising:
a laser source configured to generate and output a laser beam; and
a focus controlling component configured to control a focus of the laser beam to have a three dimensional focal pattern with multiple foci, such that as the laser beams passes through water, plasmas are induced that emit signals that interfere to form a combined signal that propagates in a desired direction.

12. The system of claim 11 , wherein the plasmas emit sonar signals.

13. The system of claim 11 , wherein the plasmas emit electromagnetic signals.

14. The system of claim 11 , wherein the focus controlling component is a phase mask.

15. The system of claim 14 , wherein the phase mask causes the multiple foci to be produced simultaneously.

16. The system of claim 15 , wherein the phase mask includes at least one of a liquid crystal spatial light modulator, a deformable mirror, a hologram grating, and an etch crystal grating.

17. The system of claim 11 , wherein the focus controlling component includes a computer-controlled beam rasterizer.

18. A method, comprising:
generating a laser beam;
controlling a focus of the laser beam to have a three dimensional focal pattern with multiple foci; and
passing the laser beam through water to induce plasmas that emit sonar signals, wherein the sonar signals interfere to form a combined sonar signal that propagates in a desired direction.

19. The method of claim 18 , wherein the focus of the laser beam is controlled so that the induced plasmas are shaped to emit the sonar signals that interfere to form the combined sonar signal that propagates in the desired direction.

20. The method of claim 19 , further comprising adjusting the direction of propagation of the combined sonar signal by adjusting the focal pattern.

Assignees

• Us Gov As Represented By The Secretary Of The Navy
• Us Navy

Inventors

• Pascoguin Bienvenido Melvin L
• Lu Ryan P
• Ramirez Ayax D

Classifications

• G01S7/524

  Transmitters · CPC title

• G01S15/88

  Sonar systems specially adapted for specific applications (seismic or acoustic prospecting or detecting G01V1/00) · CPC title

• H01J37/32412 Primary

  Plasma immersion ion implantation · CPC title

• G01S1/76 Primary

  Systems for determining direction or position line · CPC title