Design and Development of HOE-based Atomic Force Microscope with Translational and Angular measurements
Date Issued
2015
Date
2015
Author(s)
juang, Bo-Jing
Abstract
Recent years have seen increased attention being given to atomic force microscopy (AFM) in nano-scale measurement. In this dissertation, a holographic optical element (HOE) based AFM is designed and developed for operation in air and water. Unlike the bulk size and cumbersome procedures of laser beam deflection method, holographic pickup head has the advantages of easy control and simpler optical adjustment. The features of compact configuration, small size, and high sensitivity let HOE enhance the performance of AFM. Through theoretical analysis and software simulation, the translational S-curve between the light spot on photodiode and reflective plane displacement is deduced. According to the simulation results, the relevance of light spot shape, translational displacement, bending angle, and torsional angle are revealed. The detection functions of translational and angular displacements of the cantilever are demonstrated. The experiment of thermal noise spectrum verifies the stable performance and high sensitivity of holographic pickup head. The spring constant calibration of a micro cantilever is also derivative by thermal fluctuation method. AFM images of graphite display the single layer step (0.34 nm) in both air and water. The nanometer scale resolution by track error signal is also divided, thus verifying the resolution and stability of HOE-based AFM system. The images of non-contact optical profiler mode for microcircuit and tuberose epidermis tissue exemplify the feasibility and applicability of HOE-based profiler system in micron scale.
Subjects
Atomic force microscopy
Holographic optical element
Translational measurement
Angular measurement
Type
thesis
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