实验研究了圆偏振和线偏振高强度飞秒激光脉冲在正常色散材料中传输时的时空自压缩现象。实验中利用BK7玻璃作为正色散材料,比较研究了不同偏振入射情况下脉冲波形及频谱的变化规律。圆偏振光入射时,可以获得更短脉冲宽度的压缩脉冲和更窄的光谱宽度。在圆偏振光入射条件下,50 fs入射脉冲成功地自压缩到了19 fs,获得了大于2.5倍的压缩倍率。所以利用圆偏振光可以获得更短压缩脉冲,更大能量,更好光束质量的激光。

Spatiotemporal self-compression of high-intensity femtosecond pulses with linear and circular polarization in normally dispersive media is experimentally studied. In the experiment, a piece of BK7 glass plate is used as the normally dispersive media. The temporal and spectral behavior of the pulse transmitting in the glass material under different input pulse conditions is studied. The compressed pulses are much shorter in duration and narrower in spectral bandwidth by using circularly polarized pulses than linearly polarized pulses. The 50 fs pulses with circular polarization are successfully compressed to 19fs, with a compression ratio more than 2.5.