本論文提出並架設一個基於光纖法布立-佩羅干涉儀的高解析度及靈敏度的位移感測器，其目的為利用法布立-佩羅干涉儀解決奈米等級的精確度量測。此干涉儀腔體由光纖平行校正器與移動的反射鏡面組成，特別設計高效率的背向耦合。同時，利用雙腔體法布立-佩羅干涉儀擴大感測範圍，其概念為雙訊號的感測耦合。本論文比較了光纖校正器及單模光纖對於位移感測系統的影響，實驗數據表現出此光纖校正器位移感測在1500um的位移量內，達到2.08nm解析度及0.004V/nm的敏感度，並且在4mm移動量中擁有高穩定性。而單模光纖的系統表現出2.36nm的解析度與0.02V/nm的敏感度。本論文更進一步評估法布立-佩羅干涉儀之位移感測器，利用隨機信號與感測器分析之數據比對，得出高匹配的結果。實驗數據顯示當感測器工作於工作區的中心位置時，擁有最小的誤差為0.11nm，另一方面，平均誤差是7.58nm。角度偏移影響也在實驗中測試並證實，當鏡面傾角為一度時，光輸出功率下降3dB。未來改進的方向為感測器解析度的再現性，及響應圖的多重統計，使光纖法布立-佩羅干涉儀可以更精確地提供位移感測。

I propose and demonstrate a highly-sensitive motion detection based on fiber Fabry-Perot interferometry (FFPI) with resolution below 100nm. The proposed FFPI sensor solves displacement detection with precision in nano-meter scale. The interferometer is based on a fiber-optic collimator, specially designed for efficient signal back-coupling, and a discrete moving reflective mirror forming the Fabry-Perot cavity. I also compare the fiber collimators with conventional single mode fiber system in this paper. To enhance the sensing range, I propose a dual-cavity fiber Fabry-Perot interferometer, the main idea based on the interference pattern of the two signals.
Experimental results then showed that the proposed sensor is capable of sensing in a displacement range up to 1500um with resolution of 2.08nm, sensitivity of 0.004V/nm and stability within a wide area of 4mm. Meanwile, the single mode fiber system has resolution of 2.36nm with the sensitivity of 0.02V/nm. Furthermore, I evaluated the FFPI sensor with a random signal showing high correlation between reference and analyzed signal. The minimum error is 0.11nm when the sensor working in the center of working area, and average error is 7.58nm. Influence of the angular offset on FFPI performance is verified in the end of measurement.

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