Bloch spectra of one-dimensional halide perovskite photonic crystals

Matlab code to compute the Bloch spectra of a one-dimensional photonic crystal. Transfer matrices are used to compute the spectra. The crystal has alternating layers of air and a material that has dispersive properties, given by a model based on the permittivity of halide perovskites. The material parameters can be modified by altering the parameters alpha, beta and gamma. See the paper The effect of singularities and damping on the spectra of photonic crystals by Alexopoulos and Davies for details of the problem formulation and some exemplar figures.