采用空间载频干涉方法在精确测量薄片激光晶体热畸变的基础上,深入研究了射流冲击冷却系统对薄片激光晶体热畸变的影响。实验结果表明,射流冲击冷却系统引起薄片激光晶体的畸变主要是球面形变。随着抽运功率的增加,薄片激光晶体的热畸变越发严重,在抽运区中心部分,以球面形变为主,其光焦度随抽运功率的增加呈线性下降。而在抽运区的边缘,以非球面形变为主,抽运功率越高,非球面畸变就越严重。给出了493 W抽运条件下热畸变的波前畸变曲线,其均方根的重复测量精度为1.153 nm。实验结果与理论分析结果相符,该研究为薄片固体激光器谐振腔的设计和热畸变的补偿提供了重要依据。

A spatial carrier interferometry method is used for the thermo-optical aberration measurement of a thin-disk laser crystal, and the influence of jet impingement cooling system on the thermo-aberration of the thin-disk laser crystal is studied in detail. The experimental results show that the distortion of the thin-disk laser crystal caused by the jet impingement cooling system is mainly spherical deformation. As the pumping power increases, the thermo-aberration of the thin-disk laser crystal becomes worse. In the center of the pumping spot, the thermo-aberration is mainly spherical and the dioptric power decreases linearly with the increase of pumping power. In contrast, on the edge of the pumping spot, the thermo-aberration is mainly aspherical and the aspherical distortion becomes worse with the increase of pumping power. The wavefront distortion curve under a pumping power of 493 W is presented and the repeatable measurement precision of its root-mean-square is 1.153 nm. The experimental results show a good consistency with the results of theoretical analysis. It provides an important reference for the design of a stable resonator and the compensation of thermo-aberration for a disk solid-state laser.