Laser beam focusing method and system for coupled water beam optical fiber

Abstract

The invention discloses a laser beam focusing method and system for a coupled water beam optical fiber, and the method comprises the steps: setting a phase plate (6), carrying out the phase modulationof a collimated and expanded light beam on the phase plate (6), generating a non-diffracted light beam, reducing the side lobe effect of the non-diffracted light beam, and improving the energy density of a central light spot; setting a positive/negative axicon lens combination unit (7) to generate a diffraction-free light beam with a small central light spot and a long collimation area from the light beam; analyzing and optimizing the parameters of the phase plate (6) by using an annealing algorithm; and further analyzing and optimizing the laser beam collimation and expansion unit (5), the phase plate (6) and the positive/negative axicon lens combination unit (7) by combining an amplitude transmittance function of the phase plate (6), an amplitude transmittance function of the positive/negative axicon lens combination unit (7), the evaluation function and the water beam-light beam coupling condition so that the focusing effect is optimal, the quality of the light beam and the coupling efficiency of the water beam-light beam are improved, and the coupling difficulty of the water beam-light beam is reduced.

Description

technical field [0001] The invention relates to the technical field of water-conducting laser processing, in particular to a laser beam focusing method and system for coupling water beam optical fibers. Background technique [0002] Water-guided laser is a technology that uses water-beam fiber optics to conduct laser beams. Since the refractive index of water is greater than that of air, when the focused beam satisfies the critical condition of total reflection at the interface between the air and the liquid in the water beam, the water beam formed The optical fiber can confine the focused beam that is totally reflected inside it in the water beam. The focused beam propagates along the water beam fiber to the surface of the workpiece to be processed due to total reflection inside the water beam. While the laser ablates and melts the surface of the workpiece, The fine water beam impacts the workpiece to remove material and cool the workpiece, thus completing the processing of...

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a laser beam focusing method and system for coupling a water beam optical fiber, in order to solve the problems of "poor beam quality, low water beam-beam coupling efficiency, and high difficulty in water beam-beam coupling" existing in the prior art

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