Study of the ISO-FDTD algorithm for processing higher-order dielectric function in SF-FDTD

• Published in: Journal of computational electronics Vol. 23; no. 6; pp. 1391 - 1401
• Main Authors: Gu, Ke-Da, Xie, Jin, Yang, Hong-Wei
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2024; Springer Nature B.V
• Subjects: Algorithms; Differential equations; Electrical Engineering; Engineering; Exact solutions; Finite difference time domain method; Mathematical and Computational Engineering; Mathematical and Computational Physics; Mechanical Engineering; Operators (mathematics); Optical and Electronic Materials; Simulation; Theoretical; ISO-FDTD; SF-FDTD; Complex dielectric function; Higher-order
• ISSN: 1569-8025; 1572-8137
• DOI: 10.1007/s10825-024-02230-0

We use an improved shift operator finite-difference time-domain (ISO-FDTD) algorithm, previously proposed by others, to further process more complex dielectric functions including critical models and several higher-order Lorentz models that we fitted ourselves. These function models have a total of 6–8 sub-terms, and each sub-term consists of two complex poles (Lorentz model). This work supports the universal applicability of the ISO-FDTD algorithm for processing higher-order complex dispersive materials. We applied this ISO-FDTD algorithm in split-field FDTD (SF-FDTD) to simulate dispersion media under oblique incidence. The simulation results agree well with the analytical solutions. Thus, this approach provides researchers with an alternative option apart from auxiliary differential equations (ADE) or piecewise linear recursive convolution (PLRC) methods when processing high-order dispersive media in SF-FDTD.