The detailed study of the initial and collapse processes of the laser-induced cavitation requires nanosecond resolution (both nanoseconds exposure and nanoseconds interframe time) of the photography measurement system. The high-speed video cameras are difficult to achieve nanoseconds interval time. The framing and streak cameras are able to reach the nanosecond resolution, but their complex technology and expensive prices make them far from being commercially available. The present study builds a nanosecond resolution photography system based on PIV dual-head laser and conventional industrial camera. The exposure time of the photography system is controlled by the laser pulse width, which is 5 ns. The two heads of the PIV laser are operated independently thus the smallest time interval between two laser pulses can be set to less than 10 ns. A double-pulse per-exposure imaging technique is used to record the information from two laser pulses on single frame on a low-speed industrial camera. The nanosecond resolution photography system was applied to the laser-induced cavitation experiments to verify the reliability of the measurement results. The measurement of the shock wave velocity demonstrates the ability of the system to capture ultrafast phenomena, which reduces from 3611 m/s to approximately 1483 m/s within 400 ns. The experimental results also reveal the asymmetric evolution of laser-induced cavitation bubbles. The major axis of the ellipsoidal bubble has twice reversals along the laser propagation and perpendicular direction from the laser-induced breakdown to the first collapse.

激光诱导空化的初始和坍塌过程的详细研究需要摄影测量系统的纳秒分辨率（纳秒曝光和纳秒帧间时间）。高速摄像机很难达到纳秒级的间隔时间。分幅和条纹相机能够达到纳秒分辨率，但其复杂的技术和昂贵的价格使其远未商用。本研究构建了基于PIV双头激光和传统工业相机的纳秒分辨率摄影系统。摄影系统的曝光时间由激光脉冲宽度控制，为5 ns。PIV 激光器的两个头是独立操作的，因此两个激光脉冲之间的最小时间间隔可以设置为小于 10 ns。双脉冲每次曝光成像技术用于在低速工业相机的单帧上记录来自两个激光脉冲的信息。将纳秒分辨率摄影系统应用于激光诱导空化实验，验证了测量结果的可靠性。冲击波速度的测量证明了系统捕捉超快现象的能力，在 400 ns 内从 3611 m/s 减少到大约 1483 m/s。实验结果还揭示了激光诱导空化气泡的不对称演化。从激光诱导击穿到第一次坍塌，椭圆形气泡的主轴沿激光传播和垂直方向有两次反转。