角谱理论用于衍射光学元件数字仿真

Digital Simulation of Diffraction Optical Elements Based on Diffraction Angular Spectrum Theory

本文采用衍射角谱理论对衍射光学元件的光场分布进行数字计算。该理论包括两种表达方式:既可用含有传递函数的等式表达,也可用含有点扩散函数的等式表达。这两种计算方法在本质上是一致的。然而,在MATLAB计算过程中,它们又具有不同的适用条件,通过分析,将它们分为近场算法和远场算法,并且展示了它们的计算实例。结果表明,在标量衍射理论成立的条件下,不改变衍射元件抽样间隔和抽样点数,利用这两种算法能够快速、准确计算不同位置处的衍射图样。该方法对衍射光学元件像面光场分布的精确计算具有重要的意义。

Digital simulation of optical experiment has been more widespread in resent years.In this paper,diffraction angular spectrum theory is used to calculate the intensity distribution of the diffractive optical elements.This theory can be expressed by transform function,and also can be expressed by point spread function.However,two expressions vary in MATLAB.We could divide them into near field simulation method and far field simulation method.A consequence of experiment is given and discussed.It shows that they can calculate distribution of illumination in different diffractive distances accurately.These methods are important for diffraction simulations.