Characterization of graphene-based photonic crystal in THz spectrum with finite-difference time domain method

Graphene has been considered as a promising material which may find applications in the THz science. In this work, we numerically investigate tunable photonic crystals in the THz range based on stacked graphene/dielelctric layers, a complex pole-residue pair model is used to find the effective permittivity of graphene, which could be easily incorporated into the finite-difference time domain （FDTD） algorithm. Two different schemes of photonic crystal used for extending the bandgap have been simulated through this FDTD technique.