Photovoltaic effect in photorefractive holographic procedure

Abstract

Since the photorefractive effect was first discovered in 1966, and then photorefractive materials were used in many aspects, such as dynamic holography and optical phase conjugation, the band transport model has become the general explanation for such photorefraction. In this model, diffusion mechanism acts as a main role and in some cases drift mechanism (under applied field) as well as the photovoltaic effect (under uniform illumination) were added. However, experiments and theoretical analysis have shown that the photovoltaic effect should always be considered; in the case of ferroelectrics, e.g., LiNbO<SUB>3</SUB>, this effect often exceeds the diffusion and thus dominates. In addition, the circular photovoltaic effect, if it exists, is able to create a phase shift grating. Therefore, theoretically, energy can be transferred between two beams through two-wave mixing.