High-power, phased-locked, laser arrays

• US 9,748,730 B2
• Filed: 06/27/2016
• Issued: 08/29/2017
• Est. Priority Date: 02/03/2005
• Status: Active Grant

• Current Assignee: Necsel Intellectual Property Inc. (Ushio Incorporated)
• Original Assignee: Necsel Intellectual Property Inc. (Ushio Incorporated)
• Inventors: Volodin, Boris Leonidovich
• Primary Examiner(s): Zhang, Yuanda
• Application Number:
  US15/193,721
• Publication Number:
  US 20160308327A1
• Time in Patent Office: 428 Days
• CPC Class Codes: H01S 3/1305 Feedback control systems
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/065 Mode locking; Mode suppression; Mode selection ; Self pulsating
• CPC Class Codes: H01S 5/0654 Single longitudinal mode emission
• CPC Class Codes: H01S 5/141 using a wavelength selective device, e.g. a grating or etalon H01S5/146 takes precedence
• CPC Class Codes: H01S 5/148 using a Talbot cavity
• CPC Class Codes: H01S 5/4012 Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: H01S 5/4062 with an external cavity or using internal filters, e.g. Talbot filters
• CPC Class Codes: H01S 5/4068 with lateral coupling by axially offset or by merging waveguides, e.g. Y-couplers

Abstract

High-power, phased-locked, laser arrays as disclosed herein utilize a system of optical elements that may be external to the laser oscillator array. Such an external optical system may achieve mutually coherent operation of all the emitters in a laser array, and coherent combination of the output of all the lasers in the array into a single beam. Such an “external gain harness” system may include: an optical lens/mirror system that mixes the output of all the emitters in the array; a holographic optical element that combines the output of all the lasers in the array, and an output coupler that selects a single path for the combined output and also selects a common operating frequency for all the coupled gain regions.

Claims

1. A system for producing mutually-coherent operation of a plurality of light emitters, each of the emitters outputting a respective power and brightness, the system comprising:

an optical system that mixes respective beams received from each of the plurality of emitters; and

a beam-combining element that forms at least one composite beam containing a respective contribution from each of the emitters, wherein a portion of the composite beam has a selected wavelength,

wherein the composite beam is fed back in such a way that mutually coherent operation of the plurality of emitters is achieved such that the emitters phase with a phase difference that results in a coherent output beam from the system, and wherein mutually coherent operation of the plurality of emitters is achieved such that each of the emitters lases at the selected wavelength.

2. The system of claim 1, wherein a portion of the composite beam is fed back in such a way that each of the emitters receives narrowband light from every other emitter.

3. The system of claim 1, wherein the coherent output beam has a brightness that is greater than the brightnesses of the individual emitters.

4. The system of claim 1, further comprising a wavelength-selective output coupler that receives the composite beam from the beam-combining element.

5. The system of claim 4, wherein the wavelength-selective output coupler feeds back a portion of the composite beam.

6. The system of claim 5, wherein the wavelength-selective output coupler feeds back the portion of the composite beam in such a way that each of the emitters receives narrowband light from every other emitter.

7. The system of claim 6, wherein the portion of the composite beam is fed back through the beam-combining element.

8. A method for producing mutually-coherent operation of a plurality of light emitters, each of the emitters outputting a respective power and brightness, the method comprising:

mixing respective beams received from each of the plurality of emitters;

forming a composite beam containing a respective contribution from each of the emitters, and

feeding back the composite beam in such a way that mutually coherent operation of the plurality of emitters is achieved such that the emitters lase with a phase difference that results in a coherent output beam from the system,

wherein a portion of the composite beam has a selected wavelength, and wherein mutually coherent operation of the plurality of emitters is achieved such that each of the emitters lases at the selected wavelength.

9. The method of claim 8, wherein a portion of the composite beam is fed back in such a way that each of the emitters receives narrowband light from every other emitter.

10. The method of claim 8, wherein the coherent output beam has a brightness that is greater than the brightnesses of the individual emitters.

11. The method of claim 8, wherein a wavelength-selective output coupler that receives the composite beam from a beam-combining element.

12. The method of claim 11, wherein the wavelength-selective output coupler feeds back a portion of the composite beam.

13. The method of claim 12, wherein the wavelength-selective output coupler feeds back the portion of the composite beam in such a way that each of the emitters receives narrowband light from every other emitter.

14. The method of claim 13, wherein the portion of the composite beam is fed back through the beam-combining element.

15. A system for producing mutually-coherent operation of a plurality of light emitters, each of the emitters outputting a respective power and brightness, the system comprising:

an optical system that mixes respective beams received from each of the plurality of emitters; and

a beam-combining element that forms at least one composite beam containing a respective contribution from each of the emitters, and

a wavelength-selective output coupler that receives the composite beam from the beam-combining element,

wherein the wavelength-selective output coupler feeds back a portion of the composite beam in such a way that each of the emitters receives narrowband light from every other emitter, and

wherein the composite beam is fed back in such a way that mutually coherent operation of the plurality of emitters is achieved such that the emitters lase with a phase difference that results in a coherent output beam from the system.

16. The system of claim 15, wherein the coherent output beam has a brightness that is greater than the brightnesses of the individual emitters.

17. The system of claim 15, wherein the portion of the composite beam is fed back through the beam-combining element.

18. A method for producing mutually-coherent operation of a plurality of light emitters, each of the emitters outputting a respective power and brightness, the method comprising:

mixing respective beams received from each of the plurality of emitters;

forming a composite beam containing a respective contribution from each of the emitters, and

feeding back the composite beam in such a way that mutually coherent operation of the plurality of emitters is achieved such that the emitters lase with a phase difference that results in a coherent output beam from the system,

wherein a wavelength-selective output coupler receives the composite beam from a beam-combining element, and the wavelength-selective output coupler feeds back a portion of the composite beam in such a way that each of the emitters receives narrowband light from every other emitter.

19. The method of claim 18, wherein the coherent output beam has a brightness that is greater than the brightnesses of the individual emitters.

20. The method of claim 18, wherein the portion of the composite beam is fed back through the beam-combining element.