Interaction Between Two Spatial Solitons In Two-photon Photorefractive Media

Photorefractive solitons are attractive, because of their application inall-optical swiching, waveguide and optical interconnects and they can formate atlow potiacl levels, in the range of microwatts. Castro-Camus provided a model oftwo-photon photorefractive in2003. This model solves the problem that theinformation in the crystal is easy to be erased. Therefore, solitons in thetwo-photon photorefractive becomes the hotspot for the last ten years.In order to study the interaction between photorefractive spatial solitons, wegive the integral expression of bright two-photon photorefractive screening spatialsolitons and bright two-photon photorefractive photovoltaic spatial solitons in themodel of Castro-Camus and the curve of the relationship between the intensity ofthe light and their width.Using the Finite Difference Beam Propagation Method, we validate thatspatial solitons can propagate at a constant waveform in photorefractive media.We studied the influence of the biased electric field on the shape of solitons.We also studied the influence of the initial distance, initial phase and biasedelectric field on the interaction of bright two-photon photorefractive screeningsolitons. The results show that the shorter of the initial distance of two screeningsolitons is, the stronger interaction of them is; the longer of the initial distance oftwo screening solitons is, the weaker interaction of them is. Screening solitons ofthe same phase always attract each other; screening solitons of anti-phase alwaysrefuse each other. Incoherent screening solitons always attact each other. Thelarger biased electric field is, the stronger interaction between screening solitonsis; the smaller biased electric field is, the weaker interaction between screeningsolitons is.We also studied different factors on the influence of bright two-photonphotorefractive photovoltaic spatial solitons, and we found that starting lightdoesn’t influence the interaction between photovoltaic spatial solitons.We studied the interaction of three sptial solitons, and discussed theinfluence of different phase on the interaction. The results show that if the phasesof three solitons are same, they can merge into one soliton; if the phases of threesolitons are not same, they refuse each other.