The complex-Gaussian-function expansion provides a useful me thod for fast simulating the hard-edged diffracted beam propagation in the Fres nel and Fraunhofer regions,and obvious calculation errors exist only in the ext reme near field.

• 复高斯函数展开法为快速模拟硬边衍射光束在菲涅耳区和夫琅和费区的传输提供了一个有用方法 ,只是在很近的场存在着显著的计算误差。