光学参数是宏观上表征材料光学性质的物理量, 间接反映了材料的微观特性, 对光学参数准确的提取可以研究材料的微观性质和机理。 近年来, 太赫兹时域光谱技术作为一种新兴的光谱分析手段已经成为研究的热点。 由于太赫兹辐射能量低并且脉冲宽度窄（皮秒量级）, 太赫兹时域光谱技术在提取光学参数方面具有无损伤和高时间分辨率的特点。 本文总结了基于太赫兹透射和反射时域光谱技术的光学参数提取方法的研究进展, 着重阐述了几种经典方法, 分析了每种方法的优缺点, 并讨论了太赫兹时域光谱技术用于提取材料光学参数的挑战。 研究结果表明, 透射法适用于对太赫兹波吸收较弱的物质, 而反射法则适用于对太赫兹波有强烈吸收的材料。

Optical parameters which macroscopically characterize optical properties of materials indirectly reflect microscopic peculiarities of materials. Accurate extractions of optical parameters are significant for the research of microscopic behavior and macroscopic responses of materials. In recent years, as a new spectral analysis method, terahertz time-domain spectroscopy (THz-TDS) technology has become a research hotspot. Due to the low THz radiation energy and narrow pulse width (picosecond range), THz-TDS technology is nondestructive with high-temporal-resolution when being used to extract optical parameters of samples. This paper summarizes optical parameters extraction methods by using THz transmission and reflection spectroscopy technology, emphatically introduces several classic methods and analyses, along with their respective merits and demerits, and finally discusses the challenges of THz-TDS technology in optical parameters extraction. In conclusion, the transmission methods are adaptive for measuring substances which slightly absorb terahertz radiation, whereas the reflection methods are suitable for measuring materials with strong absorption capacity.