中文摘要：

讨论了部分相干成像系统空间点光强的一种近似算法——即通过特征值分解的方法将部分相干成像系统的Hopkins公式展开为N阶相干系统之和的相干系统与双线性系统算法，并提出了优化的N取值方案．该方案充分考虑了光刻系统参数对N取值的影响．实验结果证明，采用了新的N取值方案的近似算法是一种高精度算法．

英文摘要：

An approximate algorithm, SOCS algorithm, calculating point intensity of partially coherent optical imaging system, is discussed. The algorithm expands Hopkins equation into sum of N order coherent systems by eigenfunctions. An optimized strategy about how to choose N is presented, which considers the effects of parameters of the optical imaging system. The precision of the algorithm with new N-strategy is verified by experiments.