硬边衍射光束的计算模拟

Numerical simulation of hard-edged diffracted beams

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。

In the production and propagation of lasers there are more or less limiting apertures. Therefore, 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 consuming 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.