高功率脉冲在大模场掺Yb3+光纤中的自相似传输放大特性

分析了高功率脉冲在增益光纤中传输放大时非线性薛定谔方程的自相似解,得出注入光的脉宽和能量满足一定关系时,优化增益光纤的长度,才能满足种子光脉冲在增益光纤中的自相似传输放大.揭示了高功率种子光脉冲在光纤中自相似演化的特征参量.此外,模拟了注入能量为400 pJ,脉宽为200 fs,波形分别为正割、高斯以及3阶超高斯的种子光脉冲在纤芯为30μm的大模场增益光纤中的传输放大特性.结果表明3种波形的种子光脉冲的时间波形与光谱均演化为抛物形,时间波形与光谱均发生展宽,但光谱两侧均发生抖动.自相似传输放大后,脉冲为线性啁啾,易于压缩,对实现全光纤高功率超短脉冲产生系统具有重要意义.

Self-Similar Propagation and Amplification of High-Power Pulses in Large Mode Area Ytterbium Doped Fiber

The self-similar solutions of the nonlinear Schr(o)dinger equation for the high-power pulses propagated and amplified in the gain fiber are analyzed, which result showing that when the pulse duration and energy satisfied the certain relation, the seed pulse can be propagated and amplified in the gain fiber by optimizing the length of the gain fiber. The key self-similar evolution parameters of the seed pulse in the gain fiber are investigated. When the injection energy is 400 pJ and the pulse duration is 200 fs, the propagation and amplification characteristics of the secant, Gaussian, and super Gaussian seed pulses propagated and amplified in the large mode area gain fiber whose core diameter is 30 μm are numerical simulated.The results show that the temporal and spectral profiles of the three kinds of seed pulses are evolved into parabolic profiles and broadened. However, there are strong oscillations structure on the edges of the spectral profile. Moreover, the output pulse is linearly chirped parabolic pulse, which is easy to compress and has very important significance for realizing the all fiber high power ultra-short pulse generation system.