基于有限元分析方法的深紫外波段熔石英应力双折射分析

Stress Birefringence Analysis in Fused Silica at Deep Ultraviolet Waveband Based on Finite Element Simulation Method

提出一种深紫外波长条件下熔石英光学元件应力双折射的评估方法。该方法利用有限元仿真技术获取熔石英光学元件内若干截面的应力数据,结合三维插值拟合法、琼斯矩阵和路径积分方法计算光学元件引入的总相位延迟量和总方位角。在忽略样品平行度误差的情况下,所提方法对熔石英薄板样品在632.8 nm波长下相位延迟量和方位角的数值计算结果和实验结果基本一致,验证了所提方法的准确性和有效性。在此基础上,推导出相同载荷条件下,熔石英薄板在248 nm和193 nm波长下的应力双折射变化量,所得计算结果可用于分析光学元件内部应力双折射对光学系统偏振性能的影响。

In this paper,we proposed a method of evaluating the stress birefringence of fused silica in the deep ultraviolet waveband,in which the stress at several cross sections in the optical element was obtained by finite element simulation.Furthermore,the total phase retardation and azimuth introduced by the mechanical stress were calculated by three-dimensional interpolation fitting,Jones matrix,and path integration.Without considering the parallelism error of the element,the numerical results of phase retardance and azimuth at 632.8 nm were in good agreement with the experimental results,which verified the accuracy and effectiveness of the proposed method.On this basis,we derived the variation in the stress birefringence at 248 nm and 193 nm under the same loads,which can be used to analyze the effect of stress birefringence in optical elements on the polarization of optical systems.