Terahertz cross-correlation spectroscopy enables phase-sensitive measurements without the need for a laser source and, hence, presents a cost-efficient and versatile alternative to common terahertz time-domain spectroscopy approaches. This review article presents the development of this technique over the past two decades as well as applications of this approach. It is completed by a detailed mathematical description proving the irrelevance of the optical phases of the employed pump light modes. Numerical investigations of the resulting signal demonstrate the applicability and are compared to state-of-the-art measurements. Terahertz cross-correlation spectroscopy is a valuable alternative for moderate-demand applications already. Further possible improvements are discussed.

中文翻译：

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两个十年的太赫兹互相关光谱

太赫兹互相关光谱能够在不需要激光源的情况下进行相位敏感测量，因此，它提供了一种经济高效且通用的替代常见太赫兹时域光谱方法。这篇评论文章介绍了这种技术在过去二十年中的发展以及这种方法的应用。它通过详细的数学描述来完成，证明所采用的泵浦光模式的光学相位无关。结果信号的数值研究证明了其适用性，并与最先进的测量进行了比较。太赫兹互相关光谱已经是中等需求应用的有价值的替代方案。讨论了进一步可能的改进。