ArF光刻机偏振照明系统中需要采用偏振器件（沃拉斯顿棱镜），根据传统技术选用在193 nm波长透明材料设计沃拉斯顿棱镜，其分束角较小，或者分束角大时棱镜较长。为了解决这些实际问题，利用折射定律分析推导了由正晶体构成沃拉斯顿棱镜的分束角公式，还分析推导了由两种正晶体构成沃拉斯顿棱镜的分束角公式。经过分析比较，由两种正晶体构成沃拉斯顿棱镜的分束角比由单一正晶体构成沃拉斯顿棱镜有较大的提高。设计了一种用于193 nm波长的分束角达到约10°的偏振分光沃拉斯顿棱镜，另外还设计了一种用于193 nm波长的仅仅输出一束线偏振光的沃拉斯顿棱镜。这两种棱镜采用两种正晶体制作，棱镜长度适中，有利于偏振照明系统装置整体的紧凑化。

Wollaston prism is used as a polarizer in ArF lithography tool polarization illumination system. Wollaston prism is made of one kind of material used at 193 nm wavelength, the beam separation angle is very small and the prism is very long. In order to solve these practical problems, Wollaston prisms made of positive crystal are analyzed by the law of refraction, and the beam separation angle formulas are derived. A result is presented that the beam separation angle of Wollaston prism made of two kinds of positive crystal is more than that of Wollaston prism made of single positive crystal after analysis and comparison by MATLAB. A Wollaston prism with the beam separation angle of about 10° is designed at wavelength of 193 nm. Another Wollaston prism only with a output beam of linearly polarized light is designed at wavelength of 193 nm. The two prisms are made of positive crystal, the lengths of both the two prisms are medium, which can be used for the polarization illumination system in ArF lithography tool.