传统的衍射计算方法都是针对衍射场为平面的计算, 对于ICF靶腔衍射场为曲面时, 计算困难。通过比较常用衍射计算方法的优缺点, 基于层析成像的思想, 提出采用快速傅里叶变换分层计算, 并根据“最相邻”原则拟合曲面衍射场光场分布的快速计算方法。该方法可以计算出任意给定空间曲面上的光场分布, 且具有计算快速、结果精确的优点。模拟分析表明, 当分层数足够大时, 采用该方法可有效解决ICF靶腔内壁曲面光场的计算问题。

Conventional numerical methods of diffractive calculation are usually for the plane, and they are infeasible when the diffraction field applied in ICF is curved surface. In this paper, a method based on the idea of layering calculation, combining the algorithm of fast Fourier transform(FFT) with the technology of numerical fitting, has been proposed to calculate the light intensity distribution on the curved observation surface. This method can be applied to the surface with arbitrary shape, and it has comparatively high accuracy at fast calculation speed. The computation results show that the accuracy is improved as the layer number increases, and thus the method can effectively realize the light intensity distribution calculation of curved surface diffraction patterns applied in ICF.