Wang Zhanxin, Liu Jiansheng, Li Ruxin, Xu Zhizhan
State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China.
Opt Lett. 2008 Dec 15;33(24):2964-6. doi: 10.1364/ol.33.002964.
A spectral-filter method is numerically demonstrated to obtain sub-5 fs pulses by using femtosecond filamentation in fused silica. Instead of employing spectral phase compensation, by properly employing a high-pass filter to select the broadened high-frequency spectra that are located almost in phase in the tailing edge of the self-compressed pulses owing to self-steepening, as short as single-cycle pulses can be obtained. For instance, for an input pulse with a duration of 50 fs and energy 2.2 microJ, the minimum pulse duration can reach to approximately 4 fs (about 1.5 cycles) by applying a proper spectral filter.
