Design and Fabrication of a Multi-Channel Waveguide Interferometer

• Main Authors: Chib-Bin Kuo, 郭志斌
• Other Authors: 李世光
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/17151454476476290365

碩士 === 國立臺灣大學 === 應用力學研究所 === 94 === Waveguide interferometer is a special kind of evanescent wave sensors, which combines waveguide and interferometer. When a light beam propagates in a waveguide structure, the evanescent field can detect the property of surrounding dielectric media. Since the optical phase of TE and TM polarized light is influenced by both the boundary index and thickness variations to different degree, the evanescent wave can detect the boundary index and thickness variations precisely. Capitalize on this effect, the TE and TM mode polarizations can be used to provide independent information so as to deconvolute the thickness and the refractive index of bio-samples. In this dissertation, a multi-channel waveguide interferometer system that includes low-cost optical wavrguide and new optical mechanism was built. The newly proposed waveguide chip is fabricated using a plasma enhanced chemical vapor deposition (PECVD) system. Since this process is a standard semiconductor fabrication technique in silicon oxynitride on silicon, the success rate of making this chip is high. The composition of waveguide was SiO2 permeating by Ge. By adding the flux time of Ge, the index would increase. In addition, the channel structure was fabricated by wet eaching process. The optical configuration was developed based on Young’s Interferometry and the the polarization of amplelight and reference light could be exchanged in the system. Besides, a quarter wave plate, an analyzer, a CCD camera, and a personal computer consisted the phase modulation and signal analysis system of this waveguide interferometer. This newly developed multi-channeled waveguide interferometer system has been proved to have the ability of having 10-4 resolution in measuring reflective indices by measuring different glucose concentrations solutions. Furthermore, the study also verifies the capability of the ELISA experiment inherented within the newly developed system by detecting C-creative protein (CRP). By measuring both the TE and the TM modes, the newly developed system program converts the experimental results into the related bio-reaction information for further researches.