Study of Relations Between Band Gap of Photonic Crystals and the Ratio of Dielectric Index

The regular pattern of photon band gap variation with the ratio of dielectric refractive index was studied in the condition of the photonic crystal structure fixed.From the theoretical calculation of 1D photonic crystal,we conclude that the relative width of band gap get wider with the increment of the refractive index ratio.When the interval is small,they vary approximately in direction proportion.We also conclude that the variation of refractive index don′t influence the relative width of band gap if we keep the refractive index ratio fixed in addition.All of that may provide a reference for designing the photonic crystals and optical elements.