标题： 增强提示的和频生成用于分子振动纳米光谱学 显示英文标题

标题： Tip-Enhanced Sum Frequency Generation for Molecular Vibrational Nanospectroscopy

摘要： 振动和频生成（SFG）是一种非线性光谱技术，广泛用于研究表面系统的分子结构和动力学。 然而，远场观测所达到的空间分辨率受到衍射极限的限制，使得小于光波长的不均匀结构中的分子细节变得模糊。 为了克服这一限制，我们开发了一种基于扫描隧道显微镜的探针增强SFG（TE-SFG）光谱系统。 我们在环境条件下成功检测到了金基底上吸附分子的振动TE-SFG信号。 干涉SFG光谱的相位分析提供了分子取向的信息。 此外，观察到的TE-SFG信号被证实来源于探针尖端与样品基底之间的间隙内的高度局域区域。 这种方法为非线性光学纳米光谱学提供了一个新平台，为超越衍射极限的表面分子系统研究铺平了道路。 显示英文摘要

摘要： Vibrational sum frequency generation (SFG) is a nonlinear spectroscopic technique widely used to study the molecular structure and dynamics of surface systems. However, the spatial resolution achieved by far-field observations is constrained by the diffraction limit, obscuring molecular details in inhomogeneous structures smaller than the wavelength of light. To overcome this limitation, we developed a system for tip-enhanced SFG (TE-SFG) spectroscopy based on a scanning tunneling microscope. We successfully detected vibrational TE-SFG signals from adsorbed molecules on a gold substrate under ambient conditions. The phase analysis of interferometric SFG spectra provided information on molecular orientation. Furthermore, the observed TE-SFG signal was confirmed to originate from a highly localized region within a gap between the tip apex and the sample substrate. This method offers a novel platform for nonlinear optical nanospectroscopy, paving the way for the investigation of surface molecular systems beyond the diffraction limit.