公开(公告)号：US06515274B1

公开(公告)日：2003-02-04

申请号：US09620588

申请日：2000-07-20

Applicant: Martin Moskovits ,  Konstantin B. Shelimov ,  Dmitri N. Davydov ,  Thomas L. Haslett

Inventor： Martin Moskovits ,  Konstantin B. Shelimov ,  Dmitri N. Davydov ,  Thomas L. Haslett

IPC: G02B2100

CPC classification number: G01Q20/04 ,  G01Q60/22 ,  Y10S977/862

Abstract: A perpendicular-mode near-field scanning optical microscope (NSOM) utilizing a piezoelectric micro tuning fork as its height-sensing element is described. The present invention provides a method and apparatus for modifying and attaching an optical fiber to the tuning fork that allows the assembly to retain Q-factors up to 9000, substantially higher than those described so far in the literature for tuning-fork-based instruments. The method involves reducing the diameter of the cladding of the optical fiber down to the 17-25 &mgr;m using several chemical etching steps, before the fiber is attached to the tuning fork. A sharp upturn in the Q-factor is observed when the fiber diameter d drops below ˜25 &mgr;m. An analysis, which shows that the stretching force constant of a bent fiber is proportional to d4, is used to account for the great sensitivity of the Q-factor to the fiber diameter. The high Q-factors resulted in improved force sensitivity and allowed us to construct a perpendicular mode instrument without the use of additional dithering piezoelements. An improved NSOM operating in the sear force mode is also provided by thinning the optical fiber length running down the length of one of the tines to a thickness in the range from about 50 to 60 &mgr;m.

Abstract translation: 描述了利用压电微音叉作为其高度感测元件的垂直模式近场扫描光学显微镜（NSOM）。 本发明提供了一种用于将光纤修改和附接到音叉的方法和装置，其允许组件保持高达9000的Q因子，基本上高于用于音叉式仪器的文献中迄今描述的那些。 该方法包括在将光纤连接到音叉之前，使用若干化学蚀刻步骤将光纤包层的直径减小到17-25μm。 当纤维直径d低于〜25μm时，观察到Q因子的急剧上升。 分析表明弯曲纤维的拉伸力常数与d4成比例，用于考虑Q因子对纤维直径的极大灵敏度。 高Q因子导致力敏感性的提高，并允许我们构建垂直模式仪器而不使用附加的抖动压电元件。 通过使沿着其中一个齿的长度延伸的光纤长度变薄到大约50至60μm的范围内的厚度，也可以提供以冲击力模式操作的改进的NSOM。