Two-Center Model Explains Photorefractive Properties of KNbO sub 3:Fe,
Abstract
KNbO3 has favourable photorefractive properties for applications in fast nonlinear optics such as image processing, coherent light amplification, or self-pumped phase conjugation. 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, Fe(2+) and Fe(3+), as sources and traps for the redistribution of charges. But these models cannot explain a nonlinear response of photoconductivity on light intensity already observed earlier. Measurements of photoconductivity, light-induced absorption, refractive index change and grating phase shift in a KNbO3:Fe crystal are carried out. As suggested for BaTiO3 we use a charge transport model including deep and shallow traps to explain both the photoconductivity and light-induced absorption in KNbO3:Fe looking for a complete set of model parameters.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 22, 1992
- Accession Number
- ADP006777
Entities
People
- G. Kuper
- H. Hesse
- K. Buse
- L. Holtmann
- S. Loheide
Organizations
- Osnabrück University