Computation of Photonic Bandgap in 1D Photonic Crystal using Dispersion Relation

Abstract

Two lowermost photonic bandgaps for one-dimensional photonic crystal are computed from dispersion relation. AlxGl1-xN/GaN material is considered for simulation purpose, and material composition is changed to calculate the shift of midband frequency corresponding to the photonic bandgap. Both TE and TM polarizations are considered for bandgap computation, and results are evaluated from the first principle analysis. Calculations are made in normalized scale, and thus it can be fitted in the desired frequency spectrum when calculated from plane wave expansion method. Findings are utilized for design of optical filter.