Effect of structure parameter on complete bandgap of two-dimensional long wave infrared photonic crystal

Based on plane wave expansion method, the complete band-gaps of two-dimensional long wave infrared photonic crystals photonic crystals with square, hexagonal, honeycomb and chessboard lattices are studied. The influence of the filling ratio on the peak value of relative width and complete band gap is analyzed when the structure is fixed, and also the relation between the relative width of complete band gap and refractive index of materials is discussed when the filling ratio is fixed. It is useful for materials selection and structure design of long wave infrared photonic crystal.