不同偏振飞秒激光经块状材料传输后的脉宽压缩

Pulse Compression of Differently Polarized Femtosecond Laser After Propagation in Bulk Media

实验研究了线偏振和圆偏振状态下的飞秒强激光脉冲在块状材料中的传输过程。不同偏振的激光脉冲在传输过程中得到了不同程度的光谱展宽,经色散补偿后,脉冲时域宽度均得到了压缩。详细分析了压缩脉冲的脉宽以及啁啾情况与入射激光脉冲能量之间的关系,比较了飞秒激光在线偏振及圆偏振情况下的不同压缩效果。在线偏振入射光情况下得到了最短21fs的压缩脉冲宽度,在圆偏振情况下得到的最短脉冲宽度为22fs。实验结果表明,这种光谱展宽与色散补偿方式对圆偏振光同样适用,而且圆偏振的入射激光将更有利于对更高能量的脉冲进行压缩。在色散补偿量相同的情况下,压缩效果随入射脉冲能量变化的规律符合理论估计。

The propagation of linearly and circularly polarized high-intensity femtosecond laser pulses in bulk media is experimentally investigated. The spectrum broadening is different after propagation in bulk media for different input pulse polarization. The pulse width is compressed after the dispersion compensation and the different compression results when using linearly and circularly polarized laser pulse are also compared. The effect of the input laser pulse energy on the compressed pulse width and its envelope is invertigated. The shortest compressed pulse width is 21 fs by using linearly polarized input pulses, and it is 22 fs for circularly polarized laser pulses. The experimental result shows that the spectrum broadening and dispersion compensation method is also valid when compressing circularly polarized laser pulses, which will benefit higher-energy femtosecond laser pulse compression. When the dispersion compensation is the same, the relationship between the compression result and the input laser energy agrees with the theoretical analysis.