We describe a simple, optical technique for mapping 180° domains hidden inside photorefractive crystals. We intersect two coherent light beams in the crystal. Photorefractive coupling between the two beams causes one beam to emerge with a map of all the crystal’s 180° domains imprinted upon it. We tested many BaTiO3 crystals and found that they all contained 180° domains, with the relative volume of these domains varying from 25% to 0.1%.
© 1996 Optical Society of America
Stuart MacCormack and Jack Feinberg, "Revealing 180° domains in ferroelectric crystals by photorefractive beam coupling," Appl. Opt. 35, 5961-5963 (1996)