Abstract

KNbO₃ has favourable photorefractive properties for applications in fast nonlinear optics such as image processing, coherent light amplification, [1] or self-pumped phase conjugation [2]. Desirable is the optimization of the sensitivity connected with the response time and the refractive index change. Only little is known about the centers involved in the photorefractive effect of KNbO₃. Previous models were based on the assumption of iron impurities occuring in two valence states, Fe²⁺ and Fe³⁺, as sources and traps for the redistribution of charges [1]. But these models cannot explain a nonlinear response of photoconductivity on light intensity already observed earlier [3, 4].

© 1991 Optical Society of America