一种超快时间分辨速度干涉仪的设计和理论研究

Design and theoretical research of an ultrafast time-resolved velocity interferometer

在单发、超快时间分辨的测量技术中,线性啁啾脉冲和光谱仪的结合使用是一种常见方法.本文以成像型光谱仪为记录系统,利用线性啁啾脉冲的频-时对应关系,设计了一种应用于自由面速度超快测量的速度干涉仪.理论研究了其工作原理和适用范围,该速度干涉仪可以实现皮秒量级的时间分辨,且速度灵敏度可调、易调,大大拓宽了速度干涉仪的应用范围.数值模拟了系统的测速过程,结果表明,重建速度信号与给定物体速度符合得很好,进一步验证了系统的可行性.

In single-shot, ultrafast time-resolved measurements, the combination of linear chirp pulse and spectrometer is a common way. In this paper, according to the time-frequency mapping relationship of linear chirp pulse and utilizing an imaging spectrometer as a recording system, we design a chirped pulse velocity interferometer for the ultrafast measurement of free surface velocity. Theoretical research on the principle and applicability shows that picosecond resolution is achievable and the velocity sensitivity is easily adjustable, which greatly widens applications of the velocity interferometer. The numerical simulation of the measurement process shows that reconstructed velocity signal is well consistent with the given velocity, further confirming the feasibility of the chirped pulse velocity interferometer.