This is the first volume of a set of three within the Springer Series in Optical Sciences, and is devoted to photorefractive effects, photorefractive materials, and their applications. New and often expected effects have been discovered, theoretical models developed, known effects finally explained, and novel applications proposed. Photorefractive Materials and Their Applications 1 - Basic Effects is the first of three volumes within the Springer Series in Optical Sciences. The book gives a comprehensive treatment of photorefractive effects in crystals and reviews our present understanding of the fundamental origins of the effect in a variety of materials from ferroelectrics to compound semiconductors, organic crystals, and polymers. Researchers in the field and graduate students of solid-state physics and engineering will gain a thorough understanding of the photorefractive effect and find a rich reference source. The other two volumes are: Photorefractive Materials and Their Applications 2 - Materials Photorefractive Materials and Their Applications 3 - Applications This is the first volume of a set of three within the Springer Series in Optical Sciences, and is devoted to photorefractive effects, photorefractive materials, and their applications. Since the publication of our first two Springer books on Photorefractive Materials and Their Applications (Topics in Applied Physics, Vols. 61 and 62) almost 20 years ago, a lot of research has been done in this area. New and often expected effects have been discovered, theoretical models developed, known effects finally explained, and novel applications proposed. We believe that the field has now reached a high level of maturity, even if research continues in all areas mentioned above and with new discoveries arriving quite regularly. We therefore have decided to invite some of the top experts in the field to put together the state of the art in their respective fields. This after we had been encouraged to do so for more than ten years by the publisher, due to the fact that the former volumes were long out of print.