Non-steady-state photoEMF in crystals with long relaxation times of photoconductivity

Abstract

The recently discovered effect of non-steady-state photo(EMF) is a powerful technique for the measurement of different parameters of photorefractive crystals [1-3]. The photoEMF is observed as an alternating electric current Jω through a short-circuited sample of photoconductor illuminated by a vibrating pattern of interference between two coherent waves, one of which is phase modulated with frequency ω (Fig. 1). It results from a periodic modulation of the spatial shift between the distribution of photoconductivity that followes movements of the interference pattern and the distribution of the space-charge electric field recordered through the conventional diffusion holographic mechanism in photorefractive crystals.