具小光點之微懸臂感測系統之設計與開發

Abstract

原子力顯微鏡為一廣泛被使用之高解析度顯微技術，其擷取一張影像所耗費之時間通常在數分鐘以上。為了觀測各種動態現象，近年許多研究致力於高速原子力顯微鏡之開發，其中縮小微懸臂之尺寸為一提升量測頻寬之關鍵。然而，量測超小型微懸臂需要客製化之光偏折光路系統，其缺點為光路複雜以及體積大。本論文設計開發一具小光點之微懸臂感測系統，其模組化的設計具有體積小(25.5 × 25 × 48.5 mm3)、方便更換光學元件等優點。此外，可透過加裝一平凸柱面透鏡切換光偏折式及像散式兩種量測原理。實驗利用刀緣法量測聚焦光點尺寸，結果顯示微懸臂感測系統之光點直徑小於5 μm，可應用於量測超小型微懸臂。

Atomic force microscope (AFM) is a widely used high-resolution imagining technique, which takes several minutes to obtain one image. To observe dynamic phenomena, many studies devoted to develop the high-speed AFM in recent years. The results indicate that reducing the cantilever size is a key to increase the measurement bandwidth. However, to measure the ultra-small cantilever is required a customized beam-deflection optical system, which increases the optical complication and the size. In this thesis, a cantilever detection system with a small laser spot size was developed. The modular design has the advantages of the compact size (25.5 × 25 × 48.5 mm3) and easy replacement for optical components. Moreover, the beam-deflection and astigmatic methods can be switched through adding a cylindrical lens. In the experiment, the knife-edge method was utilized to measure the laser spot size. The results shows that the spot diameter of the cantilever detection system is less than 5 μm and fits the sized of ultra-small cantilevers.