利用空心光纤探测飞秒脉冲在氩气中成丝过程中的光谱演变

Probing the spectrum evolution of femtosecond pulse filament in argon gas with a hollow fiber

采用420μm纤芯直径、18cm长的空心光纤作为探测器,在强飞秒激光在氩气中成丝的条件下,研究了成丝不同部位的光谱变化.实验结果表明由于成丝范围内不同部位的脉冲宽度不一样,导致空心光纤位于成丝的不同位置时所获得的光谱展宽也不尽相同.在成丝长度范围内的特定位置可以将50fs入射脉冲最窄压缩至24.8fs.

Spectrum evolution in the filament was experimentally demonstrated with a 420 μm diameter, 18cm length hollow fiber. The experimental results show that the spectrum evolution in filamentation result from the different pulse duration along the filamentation. In our experiment, at a particular position of the filament, the pulse can be compressed to 24.8 fs from 50 fs of the incident pulse.