Photorefractive Effect: Principles, Materials, and Near‐Infrared Holography

The article consists of two main parts: the first one contains a short summary of the photorefractive effect, discussing the phenomena and the main aspects related to practical applications, followed by a synopsis of the recent progress of photorefractive materials. The second part is devoted to one of the fastest photorefractive materials, sillenite inorganic crystals, focusing in particular on the enhanced photorefractive properties in the near‐infrared spectral range. Examples of real‐time data processing with significant recording speed, as well as realized quasi‐nondestructive holographic recording are also presented. Finally, photonic devices based on the photorefractive nonlinearity, such as optically addressed spatial light modulators and all optically controlled light valves, are discussed.