超短艾里脉冲在单模光纤中相互作用规律的研究

Study of Interaction Law Between Ultra-Short Airy Pulses in Single Mode Fibers

运用分步傅里叶变换法对适用于超短艾里脉冲的高阶耦合非线性薛定谔方程进行了求解,利用Matlab软件对超短艾里脉冲在单模光纤中传输时相互作用的演化过程进行了数值模拟。结果表明,负三阶色散效应可加快波包的渗透速度,超短脉冲可传输更远距离;正三阶色散效应可减慢超短脉冲的传输,当三阶色散系数足够大时脉冲前沿处的振荡转移到后沿处。自陡峭效应通过孤子分裂的形式使超短脉冲产生时域位移,内拉曼效应导致脉冲在波长较长一侧产生拉曼自频移,且超短脉冲的能量由前沿处转移到后沿处。自陡峭效应和内拉曼效应的共同作用导致超短脉冲产生时域位移且脉冲前沿处的能量会转移到后沿处。三阶色散效应、自陡峭效应、内拉曼效应三者同时存在时会显著影响超短艾里脉冲相互作用的自弯曲特性和自加速特性。

A high order coupled nonlinear Schrdinger equation suitable for ultra-short Airy pulses is solved by means of the split-step Fourier transform method,and the evolution of the interaction of ultra-short Airy pulses propagating in fibers is numerically simulated by Matlab software.The results show that the negative third-order dispersion effect accelerates the penetration of wave packets and makes ultra-short pulses propagate over a long distance.In contrast,the positive third-order dispersion effect slows down the propagation of ultra-short pulses,and if the third-order dispersion coefficient is large enough,the pulse oscillation is transferred from the leading edge to the trailing edge.The self-steepening effect makes ultra-short pulses generate time-domain shift in the form of soliton splitting.The intra-pulse Raman scattering effect results in a Raman self-frequency shift at the long wavelength side of the pulse,so that it can transfer the pulse energy from the leading edge to the trailing edge.Under the combined impact of the self-steepening effect and the intra-pulse Raman scattering effect,an ultra-short pulse shows a time-domain displacement and the energy at its leading edge is transferred to its trailing edge.The simultaneous existence of three effects of third-order dispersion,self-steepening and intra-pulse Raman scattering strongly influences the self-bending and self-acceleration characteristics possessed by the interaction between ultrashort Airy pulses.