用于激光二极管抽运固体激光器热畸变补偿的微变形镜特性研究

在很多高功率的激光器中,由于热效应的缘故会导致激光器的光束质量大幅下降。为了改善激光光束的动态畸变,自适应光学是一种有效的方法。作为自适应光学系统的核心部件,设计了一种可用于大功率激光二极管抽运固体激光器(DPL)热畸变补偿的新型可变形反射镜,并且通过工艺流片实际制造出有效反射面积为30 mm×30 mm,拥有49个静电驱动单元的可变形反射镜。对该微机电系统(MEMS)微变形镜的变形特性进行了详细的理论分析和模拟研究,并和实际测量结果进行了比较,得到了满意的结果。为了实现闭环控制,对微变形反射镜的光学影响函数矩阵进行了全面测量,并用得到的电压矩阵对畸变激光光束的波前进行了校正。实验结果表明,微变形反射镜可以有效地改善激光光束质量。

Study of Deformable Mirror for Compensating the Thermally Induced Aberration of Laser Diode-Pumped Solid-State Laser

Many high-power lasers typically suffer from reduced beam quality due to thermally induced aberrations. Adaptive optics is an effective way to compensate the dynamic aberration. As a key component of adaptive optics system, a novel deformable mirror with 30 mm×30 mm effective reflecting surface and 49 electrostatic actuators has been fabricated successfully for wavefront correction of high average power lasers. The characteristics of this deformable mirror is analyzed and simulated in detail and the simulation result agrees well with the measured result. To meet the requirement of closed loop control, the optical influence function matrix is measured thoroughly. Based on the matrix, the laser wavefront aberration is corrected. From the result, it is explicit that the thermally induced aberration of high-power lasers is compensated by the deformable micro-mirror.