Study for Bragg detuning effect and asymmetry of diffraction efficiency on the transmission and the reflection hologram

Bragg detuning effect and asymmetry of diffraction efficiency are serious problems if a photopolymer is used for the recording material of holographic storage. The critical reasons are bulk refractive index change and shrinkage of the recording materials. Until now, analyzing these effects bas been based on the K-sphere and the transmission hologram only or the reflection hologram only. A modified numerical model has been established explaining both holograms together and its results are well matched with experimental results. Bulk refractive index change causes + directional angle detuning on the transmission and reflection holograms. Material shrinkage leads to + directional angle detuning on the transmission hologram, but - directional angle detuning on the reflection hologram. The measured data are matched with Bragg detuning effect on the transmission and the reflection holograms with the proper the bulk refractive index change and shrinkage ratio of the material. For the asymmetry of diffraction efficiency, attenuated grating of material has also been considered. And asymmetries are reproduced on both holograms using absorption coefficient of attenuated grating.