This monograph collects together papers by leading researchers in the field of photorefractive nonlinear optics. All of the works are presented by eminent researchers in their field and cover topics such as wave mixing in nonlinear optical materials; photorefractive semiconductors; organic photorefractive materials and volume holographic storage. Progress in Photorefractive Nonlinear Optics consists of chapters written by authors all serving as invited speakers to the Waseda International Symposium on Phase Conjugation and Wave Mixing held in Japan in 1997. This integrated collection of papers will be vital reading for all researchers or students of Master's level and above in the fields of optics, physical chemistry and material science.