The band structures of two-dimensional(2D)gyromagnetic photonic crystals(PCs)are analyzed by a modified finite difference time domain(FDTD)method.A special implementation is used to tackle the magnetic constitution equation.This method avoids the discretizing complexity in the time domain caused by nonlinear frequency dependence of anisotropy permeability tensor,and therefore keeps the fully explicit nature of the original FDTD method.Our implementation is proved by the band structure calculations using other methods and the transmission measurements of 2D gyromagnetic PC involving circular ferrite rods and square rods.
