基于物理模型的高功率光学元件中频误差控制算法

Intermediate frequency error control algorithm for high power optical elements based on physical model

高功率光学元件中频误差会拓宽光学元件中央亮斑,导致出现非线性自聚焦现象,提出基于物理模型的高功率光学元件中频误差控制算法,设计物理模型通过粗-精两重控制过程,粗控制端利用双频激光干涉仪,定位高功率光学元件的光束位移;依据定位出的光束位移,通过精控端和粗控端的初始封闭力调整两端抛光盘压电触动器的伸缩量,校正抛光导轨垂直方向直线度误差,控制高功率光学元件中频误差。经过实验分析发现,通过该物理模型控制高功率光学元件中频误差后,中频误差功率谱密度显著降低,元件中频误差峰谷值和均方根数值最低值分别是0.161λ和0.018λ,控制效果好。

The intermediate frequency error of high-power optical elements will widen the central bright spot of optical element,leading to the phenomenon of non-linear self-focusing.A physical model based high-frequency optical element intermediate-frequency error control algorithm is proposed.The physical model is designed to pass the coarse-fine dual control process.The dual-frequency laser interferometer is used to locate the beam displacement of high-power optical components.According to positioned beam displacement,the expansion and contraction of the piezoelectric actuators on both ends of the polishing disc are adjusted by initial closing force of the fine control end and the coarse control end.The straightness error of the vertical direction of polishing guide rail is corrected,and the intermediate frequency error of the high power optical element is controlled.After experimental analysis,it is found that after controlling the intermediate frequency error of the high-power optical element through this physical model,the power spectral density of the intermediate frequency error is significantly reduced,and the minimum values of the peak and valley values and the root mean square value of the intermediate frequency error of the element are 0.161λand0.018λ,respectively.The control effect is good.