在基于夏克-哈特曼波前传感器的深紫外物镜系统波像差检测中，均匀高亮度的照明光束是实现纳米精度波像差检测的关键。采用时域有限差分法和部分相干性理论对随机排列微孔阵列衍射波前的强度对比度进行了优化。与周期排列微孔阵列相比，采用随机排列微孔阵列，可获得更加光滑的衍射波前强度分布；对单个微孔衍射波前的分析表明，微孔直径越大衍射波前强度对比度越大；衍射波前强度对比度在双孔间为74 nm 时达到最大值。分析计算得出，为获得满足纳米精度波像差检测强度对比度要求的波前，随机排列微孔阵列中宜采用直径170 nm 的微孔，且微孔间距大于等于306 nm，此时，微孔阵列中微孔个数为428，衍射波前强度对比度为11.70。

The uniform and high brightness illumination light is the key for testing the projection objective lens in deep ultraviolet region with nanometer accuracy by using the method of Shack-Hartmann wavefront sensor. The intensity contrast of the wavefront diffracted by the random arrangement pinhole array is optimized by using finitedifference time domain method and the theory of partial coherence. The wavefront diffracted by the pinhole array with random arrangement is smoother compared with that with periodic arrangement. Analyzing the wavefront diffracted by the single pinhole shows that the larger the pinhole diameter is, the bigger the intensity contrast of the wavefront will be. The intensity contrast of the wavefront diffracted by double pinholes reaches to maximum value when their separation is 74 nm. The calculation and analysis show that, to obtain the wavefront whose intensity contrast meets the requirement of nanometer accuracy wavefront error metrology, the diameters of the pinholes in pinhole array with random arrangement should be 170 nm and their separations should not be less than 306 nm. In this case, there are 428 pinholes in the pinhole array, and the intensity contrast of the wavefront diffracted by them is 11.70.