Systems and methods for diffractive coherent laser combining

Patent metadata

Field	Value
Publication number	US-12332509-B2
Application number	US-202117237384-A
Country	US
Kind code	B2
Filing date	Apr 22, 2021
Priority date	Apr 29, 2020
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

This disclosure provides systems, methods, and apparatus related to optical systems. In one aspect, a method includes: generating a plurality of laser beams; receiving the plurality of laser beams at the point at a diffractive optical element, the diffracting optical element diffracting the plurality of laser beams to generate a plurality of output laser beams including a central laser beam and a plurality of side laser beams; measuring a power of at least two of the plurality of output laser beams generated by the diffractive optical element; determining a phase error in laser beams of the plurality of laser beams from the power of the at least two of the plurality of output laser beams; and changing the phase N−1 laser beams of the plurality of laser beams, with N being a number of the plurality of laser beams.

First claim

What is claimed is:

1. An optical system comprising:
an optical source operable to generate a plurality of laser beams, each laser beam of the plurality of laser beams being a continuous-wave laser beam;
a plurality of phase shifters, each phase shifter operable to shift a phase of one of the plurality of laser beams generated by the optical source;
a diffractive optical element, the diffractive optical element operable to receive the plurality of laser beams and to diffract the plurality of laser beams to generate a plurality of output laser beams including a central laser beam and a plurality of side laser beams;
a detection device operable to measure a power of at least two of the plurality of output laser beams; and
a control system operable to determine, using a deconvolution method, a phase error in a laser beam of the plurality of laser beams from the power of the at least two of the plurality of output laser beams, and operable to direct N−1 phase shifters of the plurality of phase shifters to change a phase laser beams of the plurality of laser beams to increase a power of the central laser beam, with N being a number of the plurality of laser beams generated by the optical source.

2. The optical system of claim 1 , wherein the detection device comprises a camera or a photodiode array.

3. The optical system of claim 1 , wherein the optical source comprises a plurality of optical sources.

4. The optical system of claim 1 , wherein the diffractive optical element comprises a transmissive optical element.

5. A method comprising:
(a) generating a plurality of laser beams, each laser beam of the plurality of laser beams being a continuous-wave laser beam, the plurality of laser beams being coherent, each laser beam of the plurality of laser beams having a phase, and each laser beam of the plurality of laser beams converging at a point;
(b) receiving the plurality of laser beams at the point at a diffractive optical element, the diffractive optical element diffracting the plurality of laser beams to generate output laser beams including a central laser beam and a plurality of side laser beams;
(c) measuring a power of at least two of the plurality of the plurality of output laser beams generated by the diffractive optical element;
(d) determining, using a deconvolution method, a phase error in laser beams of the plurality of laser beams from the power of the at least two of the plurality of output laser beams; and
(e) changing the phase of N−1 laser beams of the plurality of laser beams generated in operation (a) to increase a power of the central laser beam, with N being a number of the plurality of laser beams generated in operation (a).

6. The method of claim 5 , wherein laser beams of the plurality of laser beams are arranged in a one-dimensional array or a two-dimensional array prior to converging at the point.

7. The method of claim 5 , wherein the power of the central laser beam is maximized.

8. The method of claim 5 , wherein a power of each laser beam of the plurality of laser beams is about 0.1 milliwatts to 10 kilowatts.

9. The method of claim 5 , wherein the measuring the power is performed with a camera or a photodiode array.

10. The method of claim 5 , wherein the diffractive optical element comprises a transmissive optical element.

11. The method of claim 5 , wherein the plurality of laser beams is generated by a single laser beam passing through a beam splitter.

12. The method of claim 5 , wherein the plurality of laser beams is generated by a plurality of optical sources.

13. The optical system of claim 1 , wherein the plurality of phase shifters comprise fiber phase shifters or free space phase shifters.

14. The optical system of claim 1 , wherein the power of the central laser beam is maximized.

15. The optical system of claim 1 , wherein a power of each laser beam of the plurality of laser beams is about 0.1 milliwatts to 10 kilowatts.

16. The optical system of claim 1 , further comprising:
a beam splitter, the beam splitter operable to generate the plurality of laser beams from a single laser beam from the optical source.

17. The optical system of claim 1 , further comprising:
a plurality of amplifiers, wherein each amplifier is operable to amplify one of the plurality of laser beams from each of the phase shifters; and
a plurality of collimators, wherein each collimator is operable to collimate one of the plurality of laser beams from each of the amplifiers.

18. The optical system of claim 17 , wherein a plurality of optical fibers transport each laser beam of the plurality of laser beams from the plurality of amplifiers to the plurality of collimators.

19. The optical system of claim 1 , further comprising:
a beam splitter, the beam splitter operable to direct the plurality of output laser beams to the detection device.

20. The optical system of claim 1 , wherein the control system includes a field-programmable gate array (FPGA), a digital-to-analog converter (DAC), and piezoelectric amplifiers.

Assignees

• Univ California

Inventors

• Du Qiang
• Wilcox Russell B
• Zhou Tong
• Doolittle Lawrence R
• Huang Gang
• Li Derun

Classifications

• H01S3/06754

  Fibre amplifiers (H01S3/06708 takes precedence) · CPC title

• H01S3/0085

  Modulating the output, i.e. the laser beam is modulated outside the laser cavity · CPC title

• H01S3/23

  Arrangements of two or more lasers not provided for in groups H01S3/02 - H01S3/22, e.g. tandem arrangements of separate active media · CPC title

• G02F2203/50

  Phase-only modulation · CPC title

• G02B27/1086

  operating by diffraction only · CPC title