非线性色散对孤子在有机高聚物中的形成及传输特性的影响的理论研究

Theoretical Study of the Effect of Delayed Nonlinear Response Time on Formation and Propagation of Soliton in Organic Polymers:PPQ

本文采用包含延迟非线性响应时间（即等效的非线性色散）的非线性薛定谔方程，利用数值模拟从理论上系统地分析了非线性色散对孤子在有机高聚物中的形成及传输特性的影响，结果表明当有机高聚物具有较大的非线性色散时，与在一般无机材料光纤等具有较弱非线性色散下形成飞秒孤子的峰值功率条件相比较，必须较大地提高峰值功率才能实现非线性色散、群速度色散、自相位调制三者相互补偿下的孤子传输．另外，孤子自频移和孤子分裂随非线性色散的增大先增大后减小．

Organic polymers are attractive nonlinear materials because of their both large nonlinear coefficient and ultrafast response time. By use of the modified nonlinear Schrodinger equation, we have investigated numerically the effect of nonlinear dispersion, i.e., delayed nonlinear response time, as well as those of second-and thirdorder dispersion, on the formation and propagation of femtosecond optical soliton in organic polymers-PPQ. It has been shown that nonlinear dispersion has significant effect on the formation of soliton. The red-shift in frequency domain and the splitting in time domain of soliton due to nonlinear dispersion increase with the increasing of delayed nonlinear response time primarily, and then decrease when the delayed nonlinear response time exceeds a certain value.