The Influence Of Higher-order Perturbation On Propagation Properties Of Bright Soliton-like Pulse In Optical Fibers

This paper firstly makes a brief introduction to the origin, current research and prospect of optical fiber communication and the theory of laser transmit in fibers. By using the method of variational principle it deduces the evolution equations for the parameters [amplitude(A),frequency band width(a), chirp(b), frequency(ω), center position(ξ), phase(φ)] of bright-soliton-like pulses in common situation, in situation of without perturbation, small dielectric loss, higher-order dispersion, the fifth-order nonlinear and couple-interaction. Based on these equations it discusses the evolution of the parameters when distance change, gets the curves of relationship between frequency band width and distance, between chirp and frequency band width in the situation of without perturbation, higher -order dispersion and the fifth-order nonlinearity.The conclusions are:(1) The effects of initial chirp exist in all cases while bright-soliton-like pulses transmitting in fibers;(2) The small dielectric loss affects the evolution of phase to distance, it led to the decrease of power of bright-soliton-like Pulses;(3) Higher-order dispersion widens the width of bright-soliton-like pulses, aggravates the nonlinear shift of chirp, frequency and phase;(4) The fifth-order nonlinearity compresses the width of bright-soliton-like pulses, aggravates the nonlinear shift of chirp, frequency and phase;(5) The coupled interaction spoils the properties of evolution of amplitude, frequency band width, chirp, frequency, center position and phase;(6) The initial chirp has a greater adverse effect than higher-order dispersion and the fifth-order nonlinearity. In order to guarantee bright-soliton-like pulses being transferred efficiently the good source of bright-soliton-like pulses and good optical fibers should be made.