Research On The Evolution And The Interactions Of Bright Spatial Solitons In A Transversely Shifted Photorefractive Crystal

During the past years, photorefractive spatial solitons have been a hot topic in the field of non-linear optical solitons. Photorefractive spatial solitons with low-power, fast response, strong nonlinear effects and other features make the experiment be easy to implement, and provide favorable conditions for further applications. Its potential applications in optical switches, optical waveguides, optical interconnects and other aspects have already attracted people’s attention. In addition, because the photorefractive solitons is easy to implement, it is often used to study the interaction between solitons of common sense. It can also prove many theories generally foreseen or unusual soliton effects and photorefractive nonlinear characteristics.This paper presents a unified theory model, which improve former theoretical system and gets a good fit with the experimental phenomena. Next, lithium niobate and strontium barium niobate crystals are induced by the shifting beam in the formation and the self-bending experiments of photorefractive spatial soliton to verify the accuracy of the model. Based on the above theory, we derive the corresponding nonlinear Schrodinger equation, and it provides a theoretical basis for the numerical analysis of the soliton profile features,the dynamic evolution and the interaction.Evolution of solitons is the basic features of optical soliton transmission, and it mainly studies beam propagation characteristics in the process of moving. In order to select an appropriate initial state in the process of evolution, firstly we investigate the outline feature of bright solitons numerically. Next, according to the photorefractive spatial soliton experiment with lithium niobate and strontium barium niobate crystal beam-induced, we simulate and analyze in detail the evolution of the soliton characteristics based on the unified physical model.Photorefractive soliton collisions and interactions with its novel physical phenomena and their applications in terms of light-control-light have aroused widespread interest. First, we introduce a shifting induced photorefractive spatial bright solitons observations configuration of the experiment, and based on the analysis of the nonlinear Schrodinger equation, we simulated numerically the nonlinear medium Gaussian space interacting solitons by fractional Fourier transform method. The results were compared with the experiment, and the effects of different phase and beam power ratio, as well as the diffusion effect to the interaction of solitons have been studied. In addition, we further simulate the interaction of multiple incident beams between solitons. The interaction characteristics of shifting induced photorefractive spatial solitons and general photorefractive spatial soliton interaction is basically the same, which is due to that their nonlinear Schrodinger equations show only the difference of the factor associated with the translational velocity. This also explains the generation of photorefractive spatial solitons induced by shifting is indeed in a steady-state, and this can verify the accuracy of the proposed physical model.