研究了太赫兹散射式扫描近场光学显微镜（Terahertz scattering-type scanning near-field optical microscopy，THz s-SNOM）对亚表面金属微纳结构的显微成像检测。首次采用自主搭建的THz s-SNOM系统对表面覆盖了六方氮化硼薄膜的金微米线进行太赫兹近场显微测量，获得了具有纳米量级空间分辨率和较高对比度的近场显微图。结合全波数值模拟，分析了THz s-SNOM探测亚表面金属微纳结构的空间分辨率、近场散射信号强度和成像对比度。研究表明，THz s-SNOM具有优良的亚表面显微成像检测能力，可应用于微纳电子器件的亚表面结构表征和缺陷检测。

We review the recent biomedical detection developments of scanning near-field optical microscopy (SNOM), focusing on scattering-type SNOM, atomic force microscope-based infrared spectroscopy, peak force infrared microscopy, and photo-induced force microscopy, which have the advantages of label-free, noninvasive, and specific spectral recognition. Considering the high water content of biological samples and the strong absorption of water by infrared waves, we divide the relevant research on these techniques into two categories: one based on a nonliquid environment and the other based on a liquid environment. In the nonliquid environment, the chemical composition and structural information of biomedical samples can be obtained with nanometer resolution. In the liquid environment, these techniques can be used to monitor the dynamic chemical reaction process and track the process of chemical composition and structural change of single molecules, which is conducive to exploring the development mechanism of physiological processes. We elaborate their experimental challenges, technical means, and actual cases for three microbiomedical samples (including biomacromolecules, cells, and tissues). We also discuss the prospects and challenges for their development. Our work lays a foundation for the rational design and efficient use of near-field optical microscopy to explore the characteristics of microscopic biology.

基于扫描探针技术设计搭建了一套散射式扫描近场光学显微系统。基于搭建的系统结构和近场信号探测原理，理论分析和实验讨论了不同因素的干扰、解调阶次、聚焦光斑等因素对近场光学信号提取的影响。为进一步验证装置性能，对纳米金颗粒和机械剥离的六方氮化硼样品进行了测试。结果表明，所搭建的装置实现了10 nm的空间分辨率，可以清晰地观察到六方氮化硼表面声子极化激元在传播-反射过程中形成的驻波现象，展示了该技术在低维纳米材料光学表征中应用的巨大应用潜力。

基于自建的太赫兹散射型扫描近场显微镜系统（THz s-SNOM），研究了其在显微表征半导体载流子浓度分布中的应用。对基于半导体硅的静态随机存取存储器（SRAM）的纳米结构进行了近场显微成像测量，并采用可见光调控本征硅样品表面的载流子浓度，实现了不同浓度（10¹⁴～10¹⁷ cm^?3）光生载流子的近场检测。结果表明，此THz s-SNOM能够对半导体微纳结构的载流子分布进行高空间分辨率的显微表征，测量结果与基于偶极子模型的计算结果具有较好的吻合度。