Incoherently coupled spatial soliton families in biased two-photon photorefractive crystals with both the linear and quadratic electro-optic effect

Different from the cases discussed preciously,nonlinear changes of refractive index in the photorefractive materials are influenced by both the linear and quadratic electro-optic effect simultaneously now.Here we present the evolution equations of one-dimension incoherently coupled spatial soliton families due to two-photon effect in biased photorefractive crystals with both the linear and quadratic electro-optic effect and discuss their existence conditions and properties in detail.Our analysis indicates that these soliton families can exist in all three possible realizations:dark-dark,bright-bright and dark-bright provided that the incident beams have the same polarization,wavelength and are mutually incoherent.Finally,the stabilities of these soliton families have been discussed by means of beam propagation methods.