建立了基于飞秒激光抽运-探测原理的时间分辨阴影成像平台,直接获取了飞秒激光烧蚀石英微孔的超快过程图像。在不同能量密度、时间延迟、脉冲数量条件下,观察到随时间延迟变化的等离子体通道衰退、冲击波膨胀和微孔伸长现象。实验结果表明,所提系统有助于飞秒激光烧蚀诱导透明介质内部微纳结构的原位观察。

A time-resolved shadowgraphic imaging system based on femtosecond laser pump and probe is established for directly imaging the ultrafast process of femtosecond laser ablating of micro-holes in silica glass. The time-delay dependent phenomena of plasma channel decay, shock wave expansion, and micro-hole stretch are observed when the energy density, time-delay, and pulse number change. The experimental results show that the proposed system is very efficient for the in situ observation of the micro-nanostructures in transparent media induced by femtosecond laser ablation.