Abstract: Using transfer matrix method, we calculated and analyzed the relationships between 1-D photonic crystal transmission spectrum and each of center wavelength and the ratio of the refractive indices of two dielectric materials of 1-D photonic crystal when the incidence angle was zero and the optical thicknesses of two dielectric materials were λ₀/4, where λ₀ is center wavelength. We also gained a method for calculating optical thicknesses and refractive indices of two mediums of 1-D photonic crystal when the band gap range of vertical incident light is certain. 

Key words: photonic crystal, transfer matrix method, band structure, relative width of band gap