Incoherently coupled screening-photovoltaic spatial soliton pairs in two-photon photorefractive media

In order to prove that there are steady-sate incoherent coupled screening-photovoltaic soliton pairs in biased two-photon photovoltaic photorefractive crystals under steady-state conditions,the coupling of two incoherent optical beams with the same polarization and wavelength in two-photon photovoltaic photorefractive crystals is theoretically studied.The result shows that these soliton pairs are established by the incoherent solitary beams with the same polarization and wavelength. The screening-photovoltaic soliton pairs can be considered as the united form of screening soliton pairs and closed-circuit photovoltaic soliton pairs.They reduce to screening soliton pairs in the absence of photovoltaic effect, whereas they become photovoltaic soliton pairs under the closed circuit condition when the bias field is not applied.It is shown that incoherently coupled dark-dark and bright-bright screening-photovoltaic soliton pairs are possible due to two-photon photorefractive effect.