近场扫描光学显微镜中一种新的切向力检测系统

A NEW SHEAR FORCE DETECTING SYSTEM IN NSOM

在近场扫描光学显微镜（ＮＳＯＭ）［１］中，近场距离控制一般采用切向力控制法。检测切向力有两种方法：光学检测法和非光学检测法。目前普遍采用非光学检测法，基本上是采用压电陶瓷管控制探针和样品的距离。本文提出一种新的切向力检测系统，利用双压电片实现近场距离控制。实验结果表明，检测灵敏度大大提高，扫描力显微（ＳＦＭ）像的分辨率可达纳米量级。

A shear force method is used for the near field distance control in a near field scanning optical microscopy (NSOM). There are two ways of detecting shear force, one is optical , another is nonoptical. At present, the nonoptical method is often used, in which a piezoelectric ceramic tube is used to control the distance between tip and sample. In this paper, we prsenent a new shear force detecting system, in which a bimorph is used to control near field distance. It is demonstrated that the detection sensitivity can be greatly improved, and the resolution of SFM(scanning force microscopy) image can reach nanometer order of magnitude.