This review discusses a relatively new technique for optical nanoimaging at visible wavelength, known as tip-enhanced Raman spectroscopy (TERS). This technique relies on the enhancement and spatial confinement of light in the close vicinity of the apex of a plasmonic nanotip. The plasmonic nanotip can be positioned on the sample and controlled by a suitable scanning probe microscopy, such as atomic force microscopy or scanning tunneling microscopy. By raster scanning the nanotip, one can obtain nanoimages with high spatial resolution. While enhancement helps measuring weak phonon modes from a tiny volume of the sample, confinement delivers extremely high spatial resolution in nanoimaging. We will discuss the technique of TERS in more detail with several applications and review the recent advances.

中文翻译：

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尖端增强拉曼光谱：技术和最新进展

这篇评论讨论了在可见光波长下进行光学纳米成像的一种相对较新的技术，称为尖端增强拉曼光谱（TERS）。该技术依赖于等离激元纳米尖端的顶点附近的光的增强和空间限制。等离子体纳米尖端可以定位在样品上并通过合适的扫描探针显微镜，例如原子力显微镜或扫描隧道显微镜来控制。通过光栅扫描纳米尖端，可以获得具有高空间分辨率的纳米图像。增强有助于从极少量的样品中测量弱声子模式，而封闭则可以在纳米成像中提供极高的空间分辨率。我们将在一些应用中更详细地讨论TERS的技术，并回顾最近的进展。