Abstract

Electrochemical reduction¹ leads to faster recording and decay times in KNbO₃ crystals. In the simplest model the only photorefractive centers considered are iron impurities in two valence states Fe²⁺ and Fe³⁺. Reduction of the crystals reduces a great majority of these impurities to the Fe²⁺ state and increases the electrical conductivity. In this work we study gratings written with short pulses in such crystals.

© 1990 Optical Society of America