Transmission type laser beam shaping system

Abstract

The invention discloses a transmission type laser beam shaping system, which comprises a transmission type phase modulation mirror, a spatial filter and a transmission type collimator, wherein an incident surface of the transmission type phase modulation mirror consists of concave and convex spaced concentric toroidal surfaces with different heights, the adjacent convex surfaces and concave surfaces correspond to adjacent peaks of a laser beam, and an emergent surface of the laser is a concave surface; the spatial filter is used for selecting modes of an output beam of the transmission type phase modulation mirror, so that the central main peak beam of the output beam can pass through, and secondary small peaks are reflected and absorbed; and the transmission type collimator is used for compressing a divergence angle of the selected main peak beam, so as to obtain single-mode laser with small divergence angle and low energy loss. The transmission type laser beam shaping system provided by the invention has the advantages of simple structure and convenient adjustment, is high in power of the fundamental mode of the obtained beam, and can be applied to a variety of laser processing processes such as laser cutting, welding and punching.

Description

technical field [0001] The invention belongs to the technical field of laser beam shaping, and more specifically relates to a transmission laser beam shaping system. Background technique [0002] The advantage of laser is good directionality, monochromaticity and coherence. In many laser applications, such as laser cutting, welding, drilling, and laser medical and other micro-precision processing, it is hoped that the laser can work in the fundamental mode state with the smallest divergence angle and the best beam quality. For many lasers with large gain media, if no mode selection measures are taken, the laser often works in a high-order transverse mode state, the energy distribution of the beam on the cross-section is uneven, and the direct output cannot achieve the expected effect. It is necessary to adjust the laser output beam. The transverse mode is selected to suppress the high-order mode, increase the proportion of the fundamental mode of the output laser, and obtai...

AI Technical Summary

Problems solved by technology

[0003] Traditional mode selection methods, such as pinhole aperture mode selection, resonant cavity parameter mode selection, unstable cavity mode selection, and micro-tilted cavity mirror mode selection, can improve the beam quality of the laser output; pinhole diaphragm mode selection can be used in the laser mode selection, but the use of pinhole diaphragms largely limits the mode volume and increases mode loss; other methods require changes to the laser itself

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