摘要

Volume hologram can be treated as a kind of photonic crystals. Because of the absorption of recording medium during construction, an actual reflection volume hologram is generally not the strict periodic. Considering the heterogeneity of structures in a volume hologram, a non-uniform volume hologram is separated into several layers, and the structure of photonic bandgaps is calculated by the method of plane wave expansion. The calculations show that the losing of periodicity induced by the heterogeneity results in the increasing of the width of the bandgaps, and it makes the wavelength selectivity of a volume hologram becomes worse, i.e., the band width becomes wider.