采用光纤技术实现拉曼光谱和扫描隧道显微镜实时联用测试

Simultaneous Raman-STM Measurements Using Optical Fiber Technique

设计并制作了与扫描隧道显微镜（STM）探头和拉曼光谱仪相适配的光纤探测装置，该装置采用配有很短焦距的自聚焦透镜以获得较大的相对孔径，并使用多束光纤以充分利用扫描隧道显微镜探针周围有限空间，提高了拉曼散射光的收集效率，获得具有较高信噪比的拉曼谱图。在该装置基础上进一步建立了拉曼-扫描隧道显微镜联用系统．初步实验表明该联用系统用于实时研究固／气和固／液界面体系是可行的，即利用扫描隧道显微镜可获得固体表面的微观形貌，同时利用拉曼光谱可获得表面吸附（反应）物种的分子结构信息，它为表面科学研究提供一种新方法。

An optical fiber probing system has been designed and manufactured with special consideration for simultaneous measurement of Raman signal and scanning tunneling microscopy (STM) image. In order to improve the collection efficiency of Raman signal, the optical fiber probe carrying one excitation fiber and five collection fibers are surrounded the STM tip to fully make use of the limited space. Moreover, the graded refractive index (GRIN) lens with very short focal length has been used to ensure larger relative aperture. With the aid of this probing system, Raman spectra with good signalto-noise (S/ N ) ratio have been obtained, and a combined base of Raman sPectroscopy and STM was constructed. The preliminary results have shown that the combined base provides a new method for in-situ and real time studies on solid/gas and solid/liquid interfaces, by which the topography of the solid surfaces and the detailed structural information of adsorbed species can be obtained simultaneously.