Of interest to scientists working in the field of optics or nonlinear physics, this book gives an overview of current developments in nonlinear photorefractive optics. It dicusses exciting discoveries, with special emphasis on transverse effects such as spatial soliton formation and interaction, spontaneous pattern formation and pattern competition in active feedback systems. Different aspects of potential applications, such as wave guiding in adaptive photorefractive solitons and techniques for pattern control for information processing, are also described. The author Professor Denz received the Lise Meitner Prize in 1993 for her dissertation on photorefractive neural networks and in 1999 the Adolf Messer Prize for the development of an optical motion detection filter.