Abstract: We used the extended Dirichlet-to-Neumann (DtN) map method to calculate the bandgap structures of two-dimensional gyroelectirc photonic crystals in terahertz band. Because the DtN map method only needed to discretize on the boundaries of the cell lattice and avoided discretization in its interior, so the number of discretization points was reduced, which made the calculation much faster. Firstly, the DtN map of a unit cell of gyroelectirc photonic crystals was constructed. Secondly, the bandgap structrue of photonic crystal was transformed into the eigenvalue problem of matrix. Finally, numerical simulation verified the effectiveness of using DtN map method to calculate the bandgap structure of gyroelectric photonic crystals.

Key words: numerical method, Dirichlet-to-Neumann map, eigenvalue problem, gyroelectric photonic crystal, photonic bandgap