Hagemann Franz, Gause Oliver, Wöste Ludger, Siebert Torsten
Institut f¨ur Experimentalphysik, Freie Universit¨at Berlin, Arnimallee 14, 14195 Berlin.
Opt Express. 2013 Mar 11;21(5):5536-49. doi: 10.1364/OE.21.005536.
The synthesis of nearly arbitrary supercontinuum pulse forms is demonstrated with sub-pulse structures that maintain a temporal resolution in the few-cycle regime. Spectral broadening of the 35 fs input pulses to supercontinuum bandwidths is attained in a controlled two-stage sequential filamentation in air at atmospheric pressure, facilitating a homogeneous power density over the full spectral envelope in the visible to near infrared spectral range. Only standard optics and a liquid crystal spatial light modulator (LC-SLM) are employed for achieving pulse compression to the sub 5 fs regime with pulse energies of up to 60 μJ and a peak power of 12 GW. This constitutes the starting point for further pulse form synthesis via phase modulation within the sampling limit of the pulse shaper. Transient grating frequency-resolved optical gating (TG-FROG) allows for the characterization of pulse forms that extend over several hundred femtoseconds with few-cycle substructures.
利用在少周期范围内保持时间分辨率的子脉冲结构，实现了几乎任意超连续谱脉冲形式的合成。在大气压力下空气中进行的可控两阶段连续丝状化过程中，将35飞秒的输入脉冲光谱展宽至超连续谱带宽，从而在可见光到近红外光谱范围内的整个光谱包络上实现均匀的功率密度。仅使用标准光学器件和液晶空间光调制器（LC-SLM），就能将脉冲压缩至5飞秒以下，脉冲能量高达60 μJ，峰值功率为12 GW。这构成了通过在脉冲整形器的采样极限内进行相位调制进一步合成脉冲形式的起点。瞬态光栅频率分辨光学门控（TG-FROG）能够表征具有少周期子结构、持续数百飞秒的脉冲形式。
