WLP‐FDTD Subcell Algorithm for Modeling General Dispersive Materials

ABSTRACT

This letter proposes a frequency‐dependent subcell technique for simulating general dispersive layers within the finite‐difference time‐domain (FDTD) method using weighted Laguerre polynomials (WLPs). By reformulating the Maxwell–Ampère equations in integral form, we derive spatially resolved update equations to precisely model the electric field in subcells containing general dispersive materials. This approach significantly reduces computation time and memory consumption for multi‐scale structured electromagnetic (EM) devices. Two numerical examples verify the method's advantages. In contrast to the conventional ADE‐WLP‐FDTD approach, it accelerates computations and lowers memory usage while maintaining comparable accuracy levels.