Photoinduced nonlinear optical effects in Nd-doped δ-BiB3O6 crystals

The studies of the second harmonic generation, Pockels effect and piezoelectricity were performed for the new synthesized δ-BiB3O6 single crystals. The incorporation of Nd3+ ions into these crystals plays an important role for the increasing of the photoinduced nonlinear optical properties. Temperature dependences of the optical and piezoelectric features showed existence of some anomalies in the vicinity of 160 K and 220 K. This may confirm a principal role of the photopolarization and of the localized impurity states which give additional contribution into the observed effect. It is crucial that the effect is dependent on the number of the photoinducing pulses. The effect is completely reversible after switching off of the photoinducing laser beam.