Steady-state bright–dark vector spatial solitons in biased photorefractive–photovoltaic crystals

Abstract

We show that bright–dark vector solitons are possible in biased photorefractive–photovoltaic crystals under steady-state conditions, which result from both the bulk photovoltaic effect and the spatially nonuniform screening of the external bias field. The analytical solutions of these vector solitons can be obtained in the case of | σ|≪1, where σ is the parameter controlling the intensities of the two optical beams. In the limit of −1< σ⩽1, these vector solitons can also be determined by use of simple numerical integration procedures. When the bulk photovoltaic effect is neglectable, these vector solitons are bright–dark vector screening solitons studied previously in the | σ|≪1 regime, and predict bright–dark vector screening solitons in the −1< σ⩽1 regime. When the external bias field is absent, these vector solitons predict bright–dark vector photovoltaic solitons in closed and open circuits.