Calculating band structures of 2-dimensional periodic dispersive medium by a new method based on plane-wave expansion method

We introduce a new numerical method, based on plane-wave expansion method, to calculate the band structures of 2-dimensional periodic structures made of dispersive medium. As an example, we calculated band diagram of magnetic photonic crystals with dispersive permeability by the method. The results are the same as the other methods, but our method is highly convergent so saves a lot of running time. Besides, the method provides an intuitive means to study the effect of the magnetic field to the bandgap of the magnetic photonic crystals.