Chong A, Liu H, Nie B, Bale B G, Wabnitz S, Renninger W H, Dantus M, Wise F W
Department of Applied Physics, Cornell University, Ithaca, New York 14853, USA.
Opt Express. 2012 Jun 18;20(13):14213-20. doi: 10.1364/OE.20.014213.
With existing techniques for mode-locking, the bandwidth of ultrashort pulses from a laser is determined primarily by the spectrum of the gain medium. Lasers with self-similar evolution of the pulse in the gain medium can tolerate strong spectral breathing, which is stabilized by nonlinear attraction to the parabolic self-similar pulse. Here we show that this property can be exploited in a fiber laser to eliminate the gain-bandwidth limitation to the pulse duration. Broad (∼200 nm) spectra are generated through passive nonlinear propagation in a normal-dispersion laser, and these can be dechirped to ∼20-fs duration.
利用现有的锁模技术，激光产生的超短脉冲带宽主要由增益介质的光谱决定。在增益介质中具有脉冲自相似演化特性的激光器能够耐受强烈的光谱展宽，这种展宽通过对抛物线型自相似脉冲的非线性吸引作用而得以稳定。在此我们表明，这种特性可用于光纤激光器中，以消除脉冲持续时间上的增益带宽限制。通过在正常色散激光器中进行被动非线性传输可产生宽带（约200纳米）光谱，并且这些光谱能够被啁啾反转至约20飞秒的持续时间。
