Abstract

Most applications for BaTiO₃ require crystals that are well poled and free from domains. Spotting 90° domains inside such crystals is easy, because the Δn ~ 0.2 refractive-index step at the domain boundary scatters light into the viewer's eye. However, 180° domains are invisible to the naked eye and require more elaborate detection techniques, such as x-ray diffraction or acid etching of the crystal faces. Recently, we described a simple, all-optical technique to map, in the two transverse directions, any 180° domains hidden inside photorefractive crystals.¹ Here we elaborate on this technique to provide a fully three-dimensional map of 180° domains hidden inside a photorefractive crystal, and we show movies of these domains in motion.

© 1996 Optical Society of America