Modulation Instability in Biased Photorefractive-Photovoltaic Crystals

We show the modulation instability of broad optical beams in biased photorefractive-photovoltaic crystals understeady-state conditions. This modulation instability growth rate depends on the external bias tield, the bulkphotovoltaic effect, and the ratio of the optical beam intensity to that of the dark irradiance. Under appropriateconditions, this modulation instability growth rate is the modulation instability growth rate studied previouslyin biased photorefractive-nonphotovoltaic crystals, and the modulation instability growth rate in open- andclosed-circuit photorefractive-photovoltaic crystals can be predicted.