Method for all-fiber Q-switching through continuous acoustooptic diffraction

Abstract

The invention discloses a method for all-fiber Q-switching through continuous acoustooptic diffraction. A plurality of groups of piezoelectric transducers act on gain fibers of a fiber laser, the piezoelectric transducers are connected with a plurality of paths of radio frequency signal sources, and each group of the piezoelectric transducers at least consist of two piezoelectric transducers; the emergence angle of a synthetic sound wave generated by a piezoelectric transducer array is changed by changing the phase of an input radio frequency signal of the piezoelectric transducer array in each group of the piezoelectric transducers, so that the emergent angle satisfies a sound wave incident angle of Bragg diffraction; with a plurality of groups of acoustooptic Bragg diffractions, the laser light in the gain fibers breaks away from the limitation of a numerical aperture, and the Q-value of the laser is reduced; and when a sound wave field formed by the piezoelectric transducers disappears, phase gratings in the gain fibers disappear, and the laser is in a high Q-value state. The method is used for solving the problem of adopting the lower incident sound wave frequency and the lower sound wave power density to finish the Q-switching of the fiber laser.

Description

technical field [0001] The invention relates to the fields of acousto-optic technology and laser technology, in particular to the Q-switching technology of fiber lasers. Background technique [0002] One of the Q-switching methods for fiber lasers is to follow the traditional acousto-optic Q-switch, collimate the oscillating laser in the fiber, pass it through the acousto-optic Q-switch, and then couple it back into the fiber. Therefore, the insertion loss is very large, generally greater than 2dB. This is a large power loss for high-power fiber lasers. [0003] If the gain fiber of the fiber laser is used as the acousto-optic interaction medium, and the acoustic excitation is directly applied to the gain fiber, when the incident sound wave is incident at the Bragg angle, Bragg diffraction can be formed. According to the coupled wave equation of acousto-optic interaction and the principle of parametric interaction, it can be known that if the Bragg diffraction is to be sat...

AI Technical Summary

Problems solved by technology

However, the current domestic acoustic transducers have a relatively low maximum frequency of sound waves and a relatively small sound wave power density, which is far from meeting the requirements for forming leakage wave diffraction.

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