Vortex light array generation method based on fiber laser coherent combination

Abstract

The vortex light array generation method based on fiber laser coherent synthesis, the seed laser beam is divided into six sub-lasers, the six sub-lasers are respectively amplified and phase-modulated, and then transmitted to the collimator array located on the emitting surface, the collimator array divides the six sub-lasers according to Arranged in a regular hexagon, spliced ​​into an array beam and collimated output, most of the array beam output from the emitting surface is transmitted to the far field in free space, and a vortex light array will be formed in the far field to collect a small part of the array beam output from the emitting surface And convert it into an electrical signal, analyze and process the electrical signal, obtain the phase control signal of the six sub-lasers, and transmit the phase control signal to the corresponding phase modulator to realize the compensation of the system phase noise and the phase regulation of the array beam. This method only uses the optical fiber phase modulator to control the piston phase of each laser, without the need to introduce complex wavefront modulation, and can give full play to the advantages of coherent combining technology in terms of power expansion and fast phase modulation.

Description

technical field [0001] The invention belongs to the technical field of fiber laser coherent combination, in particular to a method for generating a vortex light array based on fiber laser coherent combination. Background technique [0002] Fiber laser coherent combining can maintain good beam quality while increasing the output power. It is an effective way to obtain high-brightness light sources, and has broad application prospects in the fields of space optical communications, medical and health, and national defense security. In recent years, the application of fiber laser coherent combining technology has expanded from the generation of energy-concentrated combined beams to the generation of structured light fields with special amplitude, phase and polarization spatial distribution. As a typical structured light, the vortex beam has attracted extensive attention from researchers at home and abroad in recent years due to its unique hollow light intensity distribution, hel...

AI Technical Summary

Problems solved by technology

However, the power of these diffractive optical elements is limited, which limits the further improvement of the output power of the vortex beam array, and it is difficult to achieve flexible control of the vortex beam mode after some diffractive optical elements are processed.

Similar to the generation of a single vortex beam, if the coherent combination of fiber lasers is used to generate an array vortex beam, it is expected to solve the two problems of limited output power improvement and flexible mode switching.

[0005] In 2018, the applicant proposed for the first time a method of using fiber laser coherent combination to generate array vortex beams, but this method requires complex control of the wavefront of each fiber laser, and also relies on spatial optical phase modulators or other diffraction methods. Optics, so output power boost potential is limited

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