Incoherently coupled grey-grey screening-photovoltaic soliton pairs in biased photovoltaic-photorefractive crystals

The incoherently coupled grey-grey screening-photovoltaic soliton pails are predicted in biased photovoltaic-photorefractive crystals under steady-sta te conditions. These grey-grey screening-photovoltaic soliton pairs can be established provided that the incident beams have the same polarization, wa velength, and are mutually incoherent. Relevant example is presented when t he photovoltaic-photorefractive crystal is of lithium niobate type. The gre y-grey screening-photovoltaic soliton pairs can be considered as the united form of grey-grey screening soliton pairs and closed-circuit grey-grey pho tovoltaic soliton pails. They reduce to grey-grey screening soliton pairs i n the absence of photovoltaic effect. whereas they will become grey-grey ph otovoltaic pairs in the closed-circuit condition when the bias field is not applied.