Discontinuous Galerkin Time Domain Method with Dispersive Modified Debye Model and its Application to the Analysis of Optical Frequency Selective Surfaces

We develop a discontinuous Galerkin time domain (DGTD) algorithm with an experimentally validated modified Debye model (MDM) to take metal dispersion into consideration. The MDM equation is coupled with Maxwell's equations and solved together through the auxiliary differential equation (ADE) method. A Runge-Kutta time-stepping scheme is proposed to update the semi-discrete transformed Maxwell's equations and ADEs with high order accuracy. Then we employ the proposed algorithm to analyze an infinite doubly periodic frequency selective surface (FSS) operating in the optical regime that exhibits transmission enhancement due to the surface plasmatic effect. The accuracy and the efficiency enhancements are validated through a comparison with commercial simulation software. This work represents the first integration of MDM with DGTD, which enables the DGTD algorithm to efficiently analyze metallic structures in the optical regime.