基于时域有限差分算法改进卷积完全匹配层的稳定性

发布时间：2018-08-14 09:38

【摘要】：为了克服时域有限差分算法中卷积完全匹配层对消逝波吸收效果差的缺点,提出一种在卷积完全匹配层后添加特殊吸收层的方法.在不增加物体与吸收层内层距离的情况下,通过调节特殊吸收层中两个衰减因子,使其为常数,并令吸收因子逐层从1增加到10,来增强吸收层对消逝波的吸收性能.平面波垂直入射到单层光子晶体的算例表明,添加了特殊吸收层的吸收边界在与散射体相距5个网格的情况下仍能够保持计算结果收敛,而传统的吸收边界则需要相距80个网格才能保证结果收敛,说明该方法提高了对消逝波的吸收性能.进一步在结构中采用此吸收边界来计算多层光子晶体的传输特性曲线,并将其与常规方法计算所得结果做比较,两种结果吻合较好.数值算例验证了该方法的有效性和正确性.
[Abstract]:In order to overcome the disadvantage of convolutional perfectly matched layer in finite-difference time-domain (FDTD) algorithm, a method of adding special absorption layer after convolution perfectly matched layer is proposed. Without increasing the distance between the object and the inner layer of the absorption layer, by adjusting two attenuation factors in the special absorption layer to make them constant, and increasing the absorption factor from 1 to 10, the absorption performance of the absorption layer to the evanescent wave is enhanced. An example of plane wave incident vertically to a single-layer photonic crystal shows that the absorbing boundary with a special absorption layer can keep the convergence of the calculation results even if the absorption boundary is 5 grids apart from the scatterer. The traditional absorbing boundary needs 80 meshes to ensure the convergence of the results, which shows that the proposed method improves the absorption performance of evanescent waves. Furthermore, the absorption boundary is used to calculate the transmission characteristic curve of multilayer photonic crystal, and the results are compared with those obtained by conventional method. The two results are in good agreement with each other. Numerical examples show the validity and correctness of the method.
【作者单位】：安徽大学电子信息工程学院计算智能与信号处理教育部重点实验室;
【基金】：国家自然科学基金(No.61601166) 安徽自然科学基金(No.KJ2015A202) 安徽高校自然科学研究重大项目(Nos.KJ2017ZD51,KJ2017ZD02)资助~~
【分类号】：O411

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