Abstract

Potassium niobate (KNbO₃) remains the subject of considerable interest for several applications involving the photorefractive effect. During the past, materials development efforts have focused on increasing the sensitivity at near-infrared wavelengths and on decreasing the photorefractive response time^1,2. The main approach to optimize near-infrared sensitivity has been the introduction of suitable dopants in the energy band gap to provide impurity centers necesary for photoexcitation. Rh was selected among a group of dopants as the most efficient impurity to increase the photorefractive sensitivity at near-infrared wavelengths². In order to optimize photorefractive recording times, in-situ high-temperature reduced Rh-doped KNbO₃ crystals were grown. In this work, we performed optical and photorefractive characterization in the reduced samples at 860 and 1064 nm wavelengths. The photorefractive performance is compared with the non-reduced rhodium-doped crystals, as well as other photorefractive crystals.

© 1998 IEEE