波片通常用于测量光学系统的偏振效应。对于大入射角的超高数值孔径（NA）成像系统，待测光不再平行于系统光轴，而是与系统光轴有较大夹角的圆锥形光束，所以在高NA的成像系统中使用的波片不是传统的两片式零级1/4波片，而是正负晶体组合的四片式宽视场角（WVA）1/4波片。分析了WVA 1/4波片的装调角度误差（绕成像系统光轴的旋转误差和垂直于系统光轴的倾斜误差）、晶体的厚度和光轴加工误差所引起的附加相位差。分析结果显示，在NA为1.35的光刻系统中，当四片式WVA 1/4波片的装调角度误差和单片晶体光轴加工误差均为±2°时，后者比前者所引起的附加相位差大10倍以上。分析了WVA 1/4波片装调和加工误差引起的最大附加相位差对高NA光刻系统掩模面光偏振度（DOP）的影响。当WVA 1/4波片的附加相位差在±10°以内时，DOP的偏差可以控制在0.1%的范围内。

A waveplate is used to measure the polarization effects in optical systems. For a ultrahigh numerical aperture (NA) imaging system with a large angle of incidence, the light concerned may be not parallel to the optical axis of the system, but a conical light beam with a large angle to the optical axis of the system. Therefore, the conventional double-plate type 1/4 waveplate can not be used in such systems. Instead of it, a four-plate wide-viewing-angle (WVA) 1/4 waveplate composed by positive and negative crystals can be used. The additional retardation caused by WVA 1/4 plate is analyzed in assembly angle error with three direction and two manufacturing errors. It is found that when the WVA 1/4 waveplate assembly error and the optical axis error of one piece crystal are both ±2°in the lithography system of NA of 1.35, the retardation error deduced by the latter relative to the former is above ten times. The deviation of light polarization degree (DOP) on mask level of high-NA lithographer is analyzed caused by the maximum additional retardation of WVA 1/4 waveplate, which comes from assembly and manufacturing error. As a result, It is concluded that when the retardation error is in the range of ±10°, the DOP deviation can be controlled in the scope of one in a thousand.