A new numerical design for two-dimensional photonic bandgap by finite element method

A computational study of the bandgap structure in two-dimensional (2D) photonic crystals (PhCs) with both square lattice and triangular lattice has been investigated in this paper. By studying in-plane light propagation in 2D PhCs, we solve the partial differential equations (PDEs) with periodic boundary conditions by using the finite element method (FEM) in frequency domain. The numerical results show that the numerical method is efficient and convergent. Moreover, based on the finite element procedure, a new numerical design scheme has been presented to obtain a desired photonic bandgap structure, which demonstrated by a design experiment in triangular lattice.