| Abstract: | A method is introduced which allows us to predict the performance of a photorefractive material quantitatively using electron paramagnetic resonance (EPR)-based defect studies. This includes the determination of the defect densities and the parameters governing their light-induced charge changes. On this basis the effective trap densities and the photorefractive response times are calculated. All quantities can be determined without theoretical simplifications such as employed in previous approaches to the problem. The method is applied to BaTiO3 and congruently melting Ba0.77Ca0.23TiO3, both doped with rhodium. The iron defects, present as background contaminations, are fully taken into account. Their influence on the intensity saturating the space charges is calculated on this basis. The complete energy dependences of the absorption cross sections of all optically active Rh and Fe defects are given. PACS 42.70.Nq; 76.30.Mi; 78.40.-q |
