Abstract：In this paper , the numeral analy sis for the diffraction distribution from a circular phase -plate with a Gaussian beamo n the ver tical plate of the axis is made .The diffractio n beam′s effective radius and quality are obtained , the diffraction beam′s effective quality should be more than 1.
朱松林,盛正卯,李 康. 高斯光束经圆波片衍射的数值分析[J]. 浙江大学学报（理学版）, 1998, 25(2): 30-36.
Zhu Songlin Sheng Zhengmao Li Kang . Numerical Analysis of Diffraction of a Circular Phase-Plate with a Gaussian Beam. Journal of ZheJIang University(Science Edition), 1998, 25(2): 30-36.