NON-BRAGG ORDERS IN DYNAMIC SELF-DIFFRACTION ON THICK PHASE GRATINGS IN A PHOTOREFRACTIVE POLYMER

We demonstrate that recording thick holographic phase gratings in phot orefractive polymers can lead not only to very efficient Bragg diffrac tion but also to rather strong diffraction into non-Bragg orders. We s how that this effect has features drastically different from those of Raman-Nath diffraction on thin gratings. We compare the experimental r esults with a model based on the theory of dynamic self-diffraction in a photorefractive medium. Applications of this effect in devices for optical image processing are proposed. (C) 1996 Optical Society of Ame rica