Properties of screening-photovoltaic spatial solitons in biased photovoltaic-photorefractive crystals

Steady-state bright spatial solitons are predicted for photovoltaic materials with an external bias filed. These solitons, being known as the screening-photovoltaic (SP) solitons, result from both the photovoltaic effect and spatially nonuniform screening of the applied field in the biased photovoltaic-photorefractive crystal and differ from previously observed photorefractive spatial solitons in their properties and physical origin. The properties of the SP solitons are discussed in detail.