Study On Spatial Optical Solitons At The Interface Of Two Types Of Photorefractive Media

Photorefractive spatial soliton is the beam propagating forward continuously in the horizontal spatial scale in a photorefractive medium,and its formation bases on the photorefractive effect within the medium.The study of photorefractive spatial solitons has always been based on the formation and propagation of optical solitons in a medium.However,there are few studies on the formation and propagation of spatial optical solitons at the interface between two media.And there are different types of spatial optical solitons in different photorefractive media based on electro-optic effects or quadratic electro-optic effects.Based on the band transport model,this dissertation theoretically studies the spatial solitons at the interface of two photorefractive media,and discusses the influence of various physical factors on the soliton solution.The space charge field formed in the photorefractive crystal under the applied voltage is solved,and then the evolution equation of the spatial soliton and its boundary connection conditions are derived at the interface of two types of photorefractive media under one-dimensional steady state.Then,the screening soliton solutions of the bright and dark at the interface are solved without considering the diffusion effect.The conditions and properties of soliton generation are numerically fitted and analyzed.The light field equation of the beam at the interface of the photovoltaic photorefractive medium is derived.Then,the solution and existence condition of the bright and dark photovoltaic soliton without external electric field are solved.Finally,the effects of intensities of incident light and the photovoltaic field on the formation and the width of photovoltaic solitons are discussed.Compared to the photorefractive medium bases on the linear electro-optic effect,the refractive index change and the space charge field distribution bases on the quadratic electro-optic effect are different.And the transmission and evolution of the beam are also changed.The propagation evolution equation at the interface of photorefractive media bases on the quadratic electro-optic effect is derived.The bright and dark soliton solutions are solved and the existence conditions are discussed.And the influence of various physical factors on the intensity distribution of spatial solitons is discussed by numerical simulation.