Abstract

Photorefractive self focusing and self defocusing have attracted much interest in the past decade. Under illumination, photorefractive materials develop the property to exhibit a space charge field, which induces, due to the linear electro-optic effect (Pockels effect), non-linear changes in the refractive index of the material. This phenomenon is able to modify natural diffraction, allowing the optical beam to be self-focused ( or defocused) or to reach a spatial soliton. Such effects have been shown in Si_xBa_1-xNb₂O₆ (SBN) and in Bi₁₂TiO₂₀ (BTO). We present an experimental approach in the study of these phenomena in two other photorefractive crystals: KNbO₃, and LiNbO₃:Fe.

© 2001 EPS