硬边衍射光束的计算模拟

在激光的产生和传输过程中或多或少地要受到光阑的限制。因此，光束通过有硬边光阑限制光学系统传输问题的研究有重要实际意义。为此，已发展了多种模拟方法。一般情况下，对Collins公式直接数值积分是一种精确的模拟方法。但当光阑数增加时，计算变得非常繁琐和费时。使用四种简明方法，即解析公式法、递推算法、复高斯函数展开法和矩阵表示法来模拟硬边衍射光束，对这些方法的优点和使用范围作了分析．讨论了方法的改进。

Numerical simulation of hard-edged diffracted beams

In the production and propagation of lasers there are more or less limiting apertures. There- fore, the beam propagation through hard-edged apertured optical systems is of practical importance, and a variety of simulation methods have been developed. As usual, the direct numerical integration of the Collins formula provides an exact simulation method, but it becomes very cumbersome and time consumi-ng as the number of apertures increases. In this paper four concise methods, i.e., the analytical propa- gation equation, recurrence algorithm, complex Gaussian function expansion and matrix representation have been used to simulate hard-edged diffracted beams. Their advantages and applicable range are analyzed and some improvements are discussed.