The Research On The Influence Of Higher Order Nonlinear On Propagation Properties Of Optical Pulse

With the development of communication technology, the demand of information is increasing. The store capacity of traditional optical fiber transmission system gradually can not meet the requirements of business applications. It has become an inevitable trend to build all-optical communications network more economical, more reliable and higher capacity. The technology of optical soliton communication is the nonlinear and long distance all-optical communication. It accomplishes stable transmission by what strong pulse products nonlinear suppression compensating broadening of pulse dispersion in optical fiber. Based on that, if the lost fiber energy get reasonable plus, the light signal can transmit a long distance without distortion. And it will ultimately accomplish the stability of high speed optical pulse transmission.In the thesis, symmetric slit-step Fourier transform method is used in solving high order nonlinear Schr?dinger equation under a variety of high order effect. And the high order nonlinear Schr?dinger equation is also treated as the model to simulate optical pulse propagation under the influence of a variety of high order effect, including single fs optical pulse and double fs optical pulses propagation under the influence of self steeping, self frequency shift and third order dispersion, comparing and analyzing fourth order and fifth order optical pulse propagation in the environment with or without fifth order nonlinear. After considering the influence of third order dispersion, fifth order nonlinear and chirp such cases, the paper also simulates the single soliton and multi-soliton transmission propagation. Nonlinear effects can balance the influence of the lead effect caused by the negative third-order dispersion to some extent .The existence of fifth order nonlinear restrains the split of high order optical pulse under the influence of GVD. It makes high order optical pulse does not split cyclically, but compressed into a main peak and a pair of weak side lobes. Adding a high-pass filter in the transmission line will make the optical pulses along the transmission direction transmit steadily. For the optical soliton pairs which under the influence of a variety of higher order perturbation, fifth-order nonlinear will trig optical soliton pulse change cyclically, the energy is transferred between solitons, soliton interaction will be enhanced, too. However, dispersion management can improve above conditions. If dispersion is allocated reasonably, little changes will happened in the width of the optical pulse and the role of higher order nonlinear can also be suppressed. Based on that, the optical soliton pulse will not deflect in the transmission process. Compared with the traditional soliton, dispersion management has great advantages.