脉冲激光频域干涉技术在超快动力学物理中的应用

介绍了一种具有fs时间分辨力的超短脉冲激光频域干涉测试技术,详细论述了该技术的工作原理和系统构成,指出传输时间差和相位差是影响频域干涉条纹周期的主要因素。采用脉冲激光频域干涉仪测量了200 nm厚度铝膜在波长800 nm、单脉冲能量0.7 mJ、脉宽35 fs脉冲激光作用下的运动速度剖面。在单次飞秒脉冲激光作用下,铝膜自由面的运动速度峰值可达960 m/s,速度剖面的上升前沿小于5.77 ps,表明脉冲激光频域干涉技术可用于测量材料在超快脉冲激光作用下的冲击动力学参数。

Application of frequency-domain interferometry to ultrafast dynamic physics

The pulse frequency-domain interferometry is introduced as a new measurement technology with femtosecond resolution. Its working principle and system structure are elaborated, and the time difference and phase difference are pointed out as the primary factors determining the fringe period in frequency-domain interferometer. The velocity profile of an aluminium foil pumped by an 800 nm, 0.7 mJ, 35 fs laser pulse was measured by the frequency-domain interferometry. The preliminary measurement shows that the maximal velocity is 960 m/s with a rise time less than 5.77 ps in the velocity profile.