Abstract

In ferroelectric crystals like KNbO₃, LiNbO₃, BaTiO₃, SBN the wave mixing performances based on the photorefractive effect are strongly affected by the polydomain feature of the material. The 90° ferroelectric domains can be revealed with microscopy observations whereas the 180° domains can not be detected neither with a polarizing microscope nor with crossed polarizers. Optical nondestructive methods have been developped to detect antiparallel domains within the volume of the materials [1,2]. In a self pumped phase conjugation mirror, the beam of light in the crystal reflects totally on several faces. The resulting beams interact with each other to create interference gratings. The diffraction of the light on these grating results in the buid-up of the phase conjugated beam [3]. That is why to obtain high reflectivities, the monodomain feature is strongly desirable inside the volume of the crystal as well as at its faces. This work presents results on the detection and the shape of antiparallel ferroelectric domains at the c-faces of a rhodium doped BaTiO₃ crystal.

© 2000 IEEE