微粗糙光学表面与多个镶嵌粒子差值散射场特性

摘要

In order to provide a theoretical basis for nondestructive examination,a calculation model for the difference scattering fields between a slightly rough optical surface and multiple inlaid defect particles is established by the finite difference time domain(FDTD)method.The Monte Carlo method is used to solve the problem of the optical surface with roughness.Moreover,the difference radar cross section is added into the half-space model to analyze the selected calculations for the effects of si-zes,separation distances,numbers,and incident angles of the defects.T he numerical results are ana-lyzed in detail to determine the best position to find the defects in the optical surface by detecting in fixed steps of 20°for the incident angle.The work done in this paper will provide a theoretical basis and technological support for the fields of nondestructive examination,optical film,optical perform-ance design of micro-/nano-structures,among others.%本文基于时域有限差分算法,研究了微粗糙光学表面与多个镶嵌粒子的差值场光散射问题.将光学基片视为微粗糙光学表面,利用蒙特卡洛方法解决了光学表面存在粗糙度的问题,并将差值场散射理论加入到计算模型中,更好地分析了缺陷粒子的散射特性,将计算区域划分成上下两个半空间,建立了微粗糙光学表面与镶嵌多体粒子复合散射模型,并与矩量法计算结果比较验证了理论的有效性.运用此模型分析了入射角、镶嵌粒子尺寸、粒子间距、粒子个数等物性特征对微粗糙光学表面与镶嵌多体粒子差值散射场的影响.实验结果表明:在一定激光入射角下,以相同回波探测角度间距20°对光学表面进行测量能够有效地检测出缺陷粒子.本文结果为光学无损检测、光学薄膜、微纳米结构的光学性能设计等提供了理论依据和技术支持.