Studies On Steady-State Photorefractive Optical Spatial Soliton

This dissertation describes theoretical and experimental research on steady-state photorefractive spatial solitons. Starting from the photorefractive effect, we explain in detail the self-trapping mechanism of steady-state photorefractive spatial soliton. We theoretically show that the study of steady-state photorefractive spatial solitons can be changed into that of screening photovoltaic photorefractive spatial solitons. The evolution eqations of one-dimension steady-state photorefractive spatial soliton are derived. Under appropriate conditions, our analysis indicates the wave equation can be exhibited bright, dark as well as gray spatial solitons.The space-charge field with a higer-order nonlinearity in biased centrosymmetric photorefractive media is presented. When the higer-order term can be neglected, this space-charge field is that studied previously in biased centrosymmetric photorefractive media. The nonlinear wave equation with a higer-order nonlinearity is investigated in biased centrosymmetric photorefractive media, which can exhibit bright and dark spatial solitons under appropriate conditions. The stability of these spatial solitons is discussed using beam propagation methods, and it has been found that optical spatial solitons in biased centrosymmetric photorefractive media are stable against small perturbations in amplitude not broken up.The bright dark vector spatial solitons are presented in biased photorefractive photovoltaic crystals. The stability of these bright dark vector solitons is discussedusing a beam propagation method. When σ> 0 and (β + α -δ) > 0 , where σ is the parameter cont rolling the intensities of the two optical beams , α and δ are the parameters related to the photovoltaic constant, and β is the parameter related to external electric field , these bright dark vector solitons are stable in the regime of (β + α-δ) being less than a certain value. When σ < 0 and (β + α - δ) < 0 ,...