Apparatus of increasing coherent beam combination laser beam quality

Abstract

The invention discloses an apparatus of increasing coherent beam combination laser beam quality. The apparatus comprises one set of diffractive telescopic system arrays, one focusing lens and one CCD. The diffractive telescopic system arrays are formed by one set of eye lens arrays and one set of objective lens arrays. Each eye lens and each objective lens form a diffractive telescopic system unit. A unit structure adopts a Galileo telescopic system. A composition lens adopts a multistage phase type Fresnel diffraction structure. The diffractive telescopic system arrays expand incident dispersed array light beams into tangent light beams. Then a focusing lens carries out focusing, far-field coherent beam combination is realized at a focal plane position and the CCD is used to detect energy distribution of beam combination laser. The apparatus possesses the advantages that processing is easy; installation and adjustment are convenient and so on. Simultaneously, the diffractive telescopic system arrays possess high expansibility. Different arrangements and coherent laser beam combination of multi-path high fill factors can be realized.

Description

technical field [0001] The invention relates to the technical field of laser coherent beam combining, in particular to a device for increasing the array beam filling factor by using a diffractive telephoto system array, thereby improving the quality of the coherent combined laser beam. Background technique [0002] High power and high beam quality are the eternal goals of laser technology research. The laser coherent beam combining technology can disperse the Joule heat in the laser working material and avoid the thermal effect and nonlinear effect in the crystal medium when the power is too large. It is an effective way to achieve high power and high beam quality laser output. However, in laser coherent beam combining, due to the existence of coherence, the combined beam spot consists of a central main lobe and a large number of side lobes, the energy is dispersed, and the beam quality is poor. For such complex spots, high beam quality means high energy concentration, and ...

AI Technical Summary

Problems solved by technology

Among them, the amplitude-phase conversion method uses two special phase plates to suppress the number of side lobes. Since the phase plate is located at the focal plane of the lens, the focusing power density that can be tolerated is very limited, and it is impossible to achieve high-power coherent beam combining; The imaging waveguide method utilizes the self-imaging effect of multimode fiber, which is only suitable for fiber lasers, and is limited by fiber thermal damage and nonlinear effects, and cannot achieve high-power coherent beam combining; the inverse Damman grating method It utilizes the splitting characteristics of Damman beams and uses them in reverse to achieve coherent beam combining. However, this method has specific requirements for the phase of each sub-beam, and the adjustment accuracy is high, making it difficult to operate. The beam shaping method uses a special lens array to The phase and amplitude shaping of each beam is carried out separately, so that each outgoing beam is a plane wave, thereby obtaining an array beam with a high fill factor. This method is difficult to design and manufacture a lens group with both phase and amplitude shaping functions, and at the same time There is a lens splicing problem

Images