Abstract

Photorefractive effects have been observed in a variety of crystals such as BGO, SBN, KNbO₃, LiNbO₃, and BaTiO₃.¹ BaTiO₃ is the one on which a great deal of attention has been focused, because BaTiO₃ crystal possesses high photorefractive sensitivity and diffraction efficiency. Unfortunately, however, if the crystal is accidentally cooled below room temperature, its single domain state will be destroyed. Other major disadvantages of BaTiO₃ crystal are that 90° twin domains easily appear in it, and its growth is difficult. LiNbO₃ crystal has no such disadvantages, but its photorefractive sensitivity and diffraction efficiency are very low. The quality of LiNbO₃ can be improved by doping, such as doping Fe or Rh.¹

© 1990 Optical Society of America