We demonstrate an improved concept for nearly bandwidth-limited nonlinear pulse compression down to the few-cycle regime in a fiber chain with alternating sign of dispersion. Whereas the normally dispersive fiber segments generate bandwidth via self-phase modulation, the anomalously dispersive fiber segments recompress the broadened spectral bandwidth by an appropriate amount of group velocity dispersion. Nonlinear pulse compression from 80 fs input pulses to nearly bandwidth-limited 25 fs pulses at 1560 nm was achieved, resulting in a pulse compression factor of 3.2. The use of a specific dispersion-compensating fiber eliminated the impact of higher-order dispersion, such that a high spectral coherence was ensured. We show that nonlinear Schrodinger equation simulations were in good agreement with the experimental results and investigated the transfer of input fluctuations to the output. The concept is transferable to longer input pulse durations, resulting in compression factors of 83 for 10 ps input pulses.

中文翻译：

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通过色散交替光纤中的非线性压缩限制带宽的少周期脉冲

我们展示了一种改进的概念，用于将几乎带宽受限的非线性脉冲压缩到具有交替色散符号的光纤链中的几个周期状态。正常色散光纤段通过自相位调制产生带宽，而异常色散光纤段通过适当的群速度色散重新压缩加宽的光谱带宽。实现了从 80 fs 输入脉冲到 1560 nm 处接近带宽受限的 25 fs 脉冲的非线性脉冲压缩，脉冲压缩因子为 3.2。特定色散补偿光纤的使用消除了高阶色散的影响，从而确保了高光谱相干性。我们表明非线性薛定谔方程模拟与实验结果非常一致，并研究了输入波动到输出的转移。该概念可转移到更长的输入脉冲持续时间，从而使 10 ps 输入脉冲的压缩因子为 83。