线性电介质和中心对称光折变晶体界面表面波的研究

摘要

We report localized surface waves at the interface between linear dielectric and centrosymmetric photorefractive (CP) crystals. Adjusting the values of the guiding parameter δ and the propagation constant b, we can easily get three types of surface waves:delocalized surface waves, shock surface waves, and localized surface waves. When the difference between b andδexceeds a certain threshold value, the localized surface waves can form at the interface between linear dielectric and CP crystals. For positiveδvalues, the part of the energy of localized surface waves concentrated in the nonlinear CP crystals is always higher than that in the linear dielectric, and increases monotonically with b. The stability properties of the localized surface waves are investigated numerically and it is shown that they can be stable. In a given system, the orders and waveforms of localized surface waves are controlled by adjusting the variable parameters which determine the strength of nonlinear effects.%报道了中心对称光折变晶体与线性电介质界面表面波的形成及能量变化。通过调节传播常数和波导参数的方法，可以得到非局域、振荡、局域三种类型的表面波。波导参数和传播常数之差大于阈值时，线性电介质和中心对称光折变晶体界面可以形成局域表面波。波导参数为正值时，局域表面波主要聚集在中心对称光折变晶体内，随着传播常数的增大，波能量随之单调递增，表面波可以稳定传播。在给定的条件下，调节决定非线性作用强度的可变参量可以控制局域表面波模的阶数和传播波形。