Kerr缺陷一维耦合腔光波导的双稳态方向性

本文提出一种只在一层高折射率介质层中掺杂Kerr介质的一维耦合腔光波导.利用一维传输矩阵理论和非线性传输矩阵方法研究了此结构的光学双稳态.根据一维传输矩阵理论分析了此结构的线性特性,包括低频带边模的偏移及场分布的特点,讨论了此结构实现双稳态的原理.研究发现:由于缺陷层中场分布与入射光方向密切相关,而缺陷层光场的局域,将激发Kerr介质的三阶非线性效应,从而改变了缺陷层的折射率,所以不同方向的入射光具有不同的双稳态阈值.利用非线性传输矩阵方法研究了光学双稳态特性.结果表明:由于缺陷层的位置导致缺陷模正方向（由左到右）入射的场分布大于反方向（由右到左）入射的场分布,正方向的阈值低于反方向的阈值,相差一倍.

Bistable Anisotropy in One-dimensional Coupled Cavity Optical Waveguides with Kerr Defect

An one-dimensional (1D) coupled cavity optical waveguides (CCOWs) with Kerr defect was proposed.It was a Kerr medium doped into a high refractive index medium layer in CCOWs.The optical bistability (OB) of the structure was investigated by using one-dimensional transfer matrix method and nonlinear transfer matrix method.The linear properties of this structure,including the characterics of the field distribution and the shift of low-frequency band edge modes,were analyzed by one-dimensional transfer matrix method.The principle of the OB realized by the structure was discussed.It is found that different incident directions have different bistability threshold,because the refractive index of the defect layer is changed by three order nonlinear effect of Kerr medium stimulated by the localization of optical field in the defect layer.The field distribution in defect layer was related to the incident light direction.The properties of the OB were studied by the nonlinear transfer matrix method.The results indicate that the threshold of the forward direction (from left to right) is a half lower than that of the backward one (from right to left),because the localization behaviour of the forward direction is larger than that of the backward direction due to the position of the defect layer.