Studies On Stable Transmission Of Optical Pulse In Inhomogeneous Fiber Systems

Based on the nonlinear Schrodinger equation with varying coefficients and the higher-order nonlinear Schrodinger equation with varying coefficients, we investigate, analytically and numerically, the transmission of pico- and femto-second optical pulses in inhomogeneous fiber systems. And some types of exact stable solitary wave solutions under different conditions are obtained. Furthermore, the stability and the interaction of the solitary waves are studied by employing the symmetrized split-step Fourier method. This may be helpful to provide some theoretical bases for studying the stable transmission of optical pulses in real fiber or soliton control systems. The main contents are as follows:1) Following the nonlinear Schrodinger equation governing the propagation of optical pulses in ideal fiber, we introduce the nonlinear Schrodinger equation with varying coefficients and the higher-order nonlinear Schrodinger equation with varying coefficients to describe the propagation of optical fiber in inhomogeneous fiber system.2) Starting from the nonlinear Schrodinger equation with varying coefficients, we study the stable transmission of picosecond pulses in inhomogeneous fiber. We discuss the propagation of picosecond bright solitons in inhomogeneous fiber. On the basis of previous work, we present the exact dark N-soliton solution by using an appropriate mapping, and discuss the propagation properties and the interaction of picosecond dark solitons in a soliton control system in detail.3) We investigate the transmission of femtosecond pulses in inhomogeneous fiber. To compare, we first introduce the propagation of femtosecond bright solitons in inhomogeneous fiber system. Then, we solve analytically the higher-order nonlinear Schrodinger equation with varying coefficients and obtain the exact dark soliton solution. With the aid of the numerical method, we analyze the stability and the...