通过求解包含拉曼增益和自陡峭效应的高阶非线性薛定谔方程,运用MATLAB模拟了拉曼增益和自陡峭效应共同作用对孤子脉冲在各向同性光纤中传输特性的影响,结果表明,自陡峭效应会导致孤子产生时域位移,而且会使高阶孤子产生孤子分裂现象。与此同时,拉曼增益改变了孤子的传输特性,抑制了自陡峭效应,从而导致脉冲宽度增大、脉冲偏移程度减弱、高阶孤子分裂成基阶孤子所需的传输距离增大。
By solving the higher-order nonlinear Schr?dinger equation (NLSE), including Raman gain and self-steepening effect, the influence of the combined effect of Raman gain and self-steepening on the propagation characteristic of soliton pulse is simulated by the software of MATLAB. Results show that self-steepening effect can produce temporal shifts of the soliton and also can lead to the breakup of higher-order solitons through the phenomenon of soliton fission. Meanwhile, the Raman gain changes the propagation characteristic of optical soliton and inhibits the self-steepening effect, resulting in the increase in pulse width, and the decrease in pulse offset. As a result, the required propagation distance for higher-order soliton decaying into fundamental solitons is increased under the condition of Raman gain.