虹吸动态化学腐蚀法制备近场光学显微镜光纤探针的研究

基于虹吸原理 ,设计了一种动态化学腐蚀法的简易装置 ,用于制备近场光学显微镜光纤探针。在一般化学腐蚀法的基础上 ,通过改变虹吸管中水的流向和流速来有效地控制探针锥角和锥长 ,制备出多种形貌的光纤探针。与传统的静态化学腐蚀法相比 ,该法具有重复性高、探针形貌可控、操作方便、实验费用低廉、制备的探针表面光滑等优点。利用该装置 ,成功地制备出针尖尺寸 5 0～ 30 0nm ,针尖锥角在 16°～ 6 5°之间可调的光纤探针。同时 ,选择适当的液位差 ,通过一步腐蚀法制备出针尖尺寸小于 5 0nm ,针尖锥角 12 5°的双锥角光纤探针。并对可能的腐蚀机理进行了探讨。

Fabrication of Optical Fiber Probes by Dynamic Chemical Etching Based on Siphon Principle

A simple dynamic chemical etching device based on siphon principle is developed for fabrication of optical fiber probes which are commonly used in near-field optical microscopy. Probes with various shapes have been fabricated because the taper length and taper angle of the probe could be efficiently controlled through adjusting the speed and direction of water flux while etching. Compared with traditional static chemical etching, this method has the advantages such as reproducibility, controllability, convenience, lower cost, and it can make the probe surface smooth. Probes with apex diameter from 50 nm to 300 nm and taper angle from 16° to 65° have been achieved by this method. Moreover, double-taper probes with apex diameter less than 50 nm and taper anger larger than 125° could also be obtained by selecting appropriate water level difference. The mechanism of the chemical etching is discussed.