Interference Phenomena Observed on an Atomic Force Microscope Cantilever by Laser Confocal Microscopy

概要

論文の詳細を見る
We investigated interference phenomena that were observed on a cantilever bar of an atomic force microscope by using a laser confocal microscope (LCM). First, we established a simple model and calculated the fringe interval. Interference fringe patterns were observed under the following conditions: (1) changing the focus and confocal aperture of the LCM, (2) increasing the reflectance by sputtering TiO<sub>2</sub> on the cantilever bar and glass plate, and (3) changing the medium from air to water in the space between the glass plate and the cantilever. The purpose of a previous experiment was to measure the refractive index of water. It was theoretically determined that the fringe interval depended not on the height of the cantilever from the surface but on the wavelength, refractive index, and tilt angle of the cantilever. We obtained the following experimental results: (1) the fringe interval was independent of the confocal plane when using a monochromatic laser, (2) a sharpened interference fringe was observed when we used a TiO<sub>2</sub>-coated cantilever and glass plate, and (3) the refractive index of a small quantity of water could be measured.
2011-08-25