Optically induced refractive index changes in KNbO3:Fe

Abstract

The light induced index changes in KNbO₃: Fe have been investigated by the holographic technique using optical power densities up to I = 300 W/cm² at λ = 488 nm. For undoped crystals the light induced index change is smaller than 3 λ 10⁶ for all light intensities used. The index change can be drastically reduced or enhanced by applying a small dc field along the ±c axis.