| Summary: | 碩士 === 國立彰化師範大學 === 機電工程學系 === 98 === Based on total-internal reflection (TIR), a phase sensitivity-tunable optical sensing system is proposed. This thesis attempts to design a phase sensitivity-tunable optical sensing system consisting of a heterodyne light source, a Mach-Zehnder interferometer, an isosceles right-angle prism, and some quarter- and half- wave plates. When the azimuth angles of the quarter-wave plates are chosen properly, the final phase difference of the two interference signals is associated with the azimuth angle of the fast-axis of the half-wave plates, thus creating the controllable phase sensitivity. Numerical analysis demonstrates that the high phase measuring sensitivity and the small measuring range, and the low phase measuring sensitivity and the wide measuring range can be performed by selecting the suitable azimuth angle of the half-wave plates. The feasibility of the measuring method was demonstrated by the experiment results. Numerical calculations indicate that the sensitivity of 8.44～1077 degree/degree, and the measurement resolution of1.184×10-3~9.688×10-6 , can be achieved. In addition to the tunable phase sensitivity and small size TIR apparatus, this system also has the merits of high stability and high resolution due to its common-path configuration and heterodyne phase measurement.
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