太赫兹单次测量技术可以对一些超快不可逆过程进行快速测量,在蛋白质变性、核爆模拟分析等领域具有广阔的应用前景。从飞秒激光放大器发出的光脉冲分成两束并分别经过两块光栅产生波前倾斜,一束作为抽运光激发铌酸锂晶体,基于光整流效应产生高功率太赫兹波;另一束作为探测光,采用正交平衡探测法探测。利用该光路产生太赫兹脉冲并对其进行单次测量,系统的时间窗口为16.8 ps,频谱范围覆盖0.1~1.6 THz。

Single-shot measurement of terahertz pulses is mainly used to rapidly measure the terahertz spectra during ultrafast irreversible processes. It has broad prospects for applications in protein denaturation, nuclear-explosion-simulation analysis, and other fields. The optical pulse from a femtosecond laser amplifier is divided into two beams and passes through two gratings to generate a tilted wavefront. One beam is used as the pump light to excite a lithium niobate crystal and generate a high-power terahertz wave based on the optical-rectification effect. The other beam is used as the probe light. We use the crossed and balanced detection method. After the terahertz pulses are generated, we implement a single-shot measurement of terahertz pulses using the proposed light paths. The time window of the system ranges up to 16.8 ps, and the spectral range is 0.1-1.6 THz.