Nanosecond optical response to pulsed uv excitation in KNbO3

Abstract

Interband photoexcitation in photorefractive ABO3 perovskites has only recently attracted the attention of researchers. Band to band excitation of electrons can lead to fast photorefractive response times [1] and, through trapping, to the sensitisation of impurity levels in the band gap. Strong effects are observed that lead to cw photorefractive response times on the microsecond time scale [1]. Absorption changes at visible wavelengths induced by uv illumination have been observed in BaTiO3 [2].