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Research On The Propagating Characteristics Of The Self-similar Soliton Pulses In Coupled Inhomogeneous Optical Fiber System

Posted on:2015-06-21Degree:MasterType:Thesis
Country:ChinaCandidate:H J LiFull Text:PDF
GTID:2308330461985068Subject:Signal and Information Processing
Abstract/Summary:PDF Full Text Request
In recent years, producing and transmitting optical pulse with high energy, high power and strict linear chirp features is one of research hotspots in the field of fiber optics in the world, and the self-similar pulse well solved the problem of pulse intensity limit in transmission. Self-similarity is a common phenomenon in nature, it can be described by nonlinear Schrodinger equation. Self-similarity in the optical fiber is able to produce progressive impulse which energy is significantly amplified, and has very strong linear chirp and its time-domain characteristics are similar to parabolic shape under the combined action of the normal group velocity dispersion, self phase modulation and gain. Besides, in a complex nonlinear system, the emergence of the self-similar also brought a lot of clear information about the inner dynamic and studying the self-similar solution of relevant nonlinear equations is of great significance in understanding different nonlinear physical phenomena. So the research of self-similar solutions are widely used in many physical field, such as condensed matter physics, plasma physics, fluid dynamics, quantum field theory and biological physics, etc. But in the field of optics, the research of these characteristics is still in primary stage now, especially in the field of nonlinear fiber optics, the research has just started. In this paper, based on the coupled nonlinear Schrodinger equation for the model, we studied the transmission characteristics of the self-similar optical pulse propagating in the coupled inhomogeneous optical fiber system through two methods:analytical and numerical.The studied contents include the following several aspects:(1) We introduce the history and development of optical fiber communication and soliton theory, the research status and backgrounds of optical soliton communication and the applications of Self-similar optical pulse.(2) We introduce the transmission model of optical pulse in optical fiber and the numerical method when studying the transmission characteristics:split-step Fourier method and Runge-Kutta method. The paper adopts both the two methods to avoid limitations when only use the split step Fourier method.(3) We solve the theoretical model (the coupled nonlinear Schrodinger equation with variable coefficients) which governs the transmission of Self-similar optical pulses in coupled inhomogeneous optical fiber system by using the ansatz method and obtains the self-similar solutions, and analyzed the transmission characteristics of the solution in the coupled inhomogeneous optical fiber system in detail analytically and numerically. Results show that the Self-similar optical pulse can propagate stably in a coupled inhomogeneous optical fiber system when it satisfies a certain condition.(4) We solve coupled high order nonlinear Schrodinger equation with variable coefficients by using the balance principle and elliptic function method, and then numerically analyze the transmission characteristics of the solution by using split-step Fourier method and Runge-Kutta method to discuss the stabilities of the solved pulses. Results show that, as long as the parameters are selected reasonable, the pulse can propagate stably in the coupled inhomogeneous fiber system.
Keywords/Search Tags:Self-similar pulse, Optical soliton, Inhomogeneous fiber optics, Coupled nonlinear Schr(o|")dinger equation
PDF Full Text Request
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