中文摘要：

利用耦合非线性薛定谔方程（CNLSE）为非线性偏振旋转（NPE）锁模自相似光纤激光器建立了一种新的数值模型.模型中,用CNLSE描述脉冲在单模光纤中的传播,在增益光纤中同时考虑了增益带宽和增益饱和作用,用传输矩阵描述构成NPE锁模的光学元件.优化了腔内净色散和光纤长度等参数,模拟了脉冲在激光腔内的演化特性,得到了典型的自相似脉冲运行区域及特点.在最佳自相似脉冲运行区域内,得到了能量约为7nJ、脉宽约11ps、线性啁啾的抛物脉冲.比较了不同腔内净色散条件下输出脉冲的特点,给出了三阶色散对输出脉冲的影响.

英文摘要：

A numerical model for self-similar pulse nonlinear polarization rotation mode-locked fiber laser is built by utilizing coupled nonlinear Schrodinger equations （ CNLSE）. In this model, the propagation of the pulse within single mode fiber is described by CNLSE. In the gain fiber, gain bandwidth and saturable gain are both considered. Other optical components which implement NPE mode-locking are modeled by transfer matrixes. According to the optimized net cavity dispersion and length of the cavity, the evolution of the pulse along the cavity is simulated. At the same time, characteristics and the typical regime of the self- similar pulse are found. The simulation results show that pulse with 7 nJ energy, 11 ps duration, linear chirped, and of parabolic shape occurs within the optimized self-similar regime. The characteristics of the laser with different dispersion are compared. The influence of the third order dispersion on the laser is simulated.