分佈式光纖感測系統的技術，是利用桑克干涉儀感測時變物理場的原理，可以用來量測擾動物理場的位置，且具有對連續位置做監測的能力。鑑於傳統桑克干涉儀的架構，感測光纖皆為環形設計，並不易於實際環境上的佈放，且需將一半環狀光纖的長度，做物理場感應的隔離保護。所以，本文提出以同軸式的概念，作為設計的方向。並以管線洩漏聲場為物理場，進行擾動位置的偵測。同軸式系統架構的訊號可測範圍為3×10-4 ~3×10-2 ，其動態範圍為40 dB。另一方面，提出一偏振無感受的系統架構，其訊號可測範圍為1.5×10-3 ~3×10-2 ，動態範圍為26 dB。

The technique of the distributed fiber optic sensor system, the principle that we use Sagnac interferometer to sense time-varying physical field, can be used to measure the position of the disturbed physical field and have the ability of detecting continuous position. Based on the configuration of the Sagnac interferometer, sensing optic fiber is loop design, which is hard to be set in real surroundings, and a half length of loop fiber have to be the isolated protection of the physical field. Therefore, this essay brings up the In-Line conception to be the design direction. And we make use of the physical field of pipeline leak acoustic to detect disturbance position. The measurable range of systematic structure signal is 3×10-4 ~ 3×10-2 , and the dynamic range is 40 dB. On the other hand, the structure of polarization insensitive is brought up, the measurable range is 1.5×10-3 ~ 3×10-2 , and the dynamic range is 26 dB.

摘要 i
致謝 iii
目錄 iv
表目錄 viii
圖目錄 ix
符號表 xii
第一章 簡介
1.1 研究背景 1
1.2 研究動機 3
1.3 論文架構 5
第二章 感測系統之理論探討
2.1 感測原理 6
2.1.1 干涉原理 7
2.1.2 桑克干涉儀 8
2.2 感測系統之基本架構 8
2.2.1 光源單元 9
2.2.1.1 摻鉺光纖放大器自發性光源 9
2.2.1.2 光循環器 10
2.2.2 感測單元 11
2.2.2.1 感測光纖 11
2.2.2.2 2×2耦合器 12
2.2.2.3 偏振控制器 13
2.2.2.4 法拉第旋轉鏡 14
2.2.2.5 PZT相位調制器 14
2.2.3 訊號解調單元 15
2.3 系統元件的數學模型 16
2.3.1 光纖的瓊斯矩陣 17
2.3.2 法拉第旋轉鏡的瓊斯矩陣 17
2.3.3 光纖耦合器的瓊斯矩陣 18
第三章 感測系統之設計
3.1 位置偵測機制 19
3.2 系統構型的探討 22
3.2.1 系統架構是否產生訊號褪變的現象 22
3.2.2 光纖環狀結構有無環狀共振的效應 24
3.2.3 光纖環狀結構造成多組干涉光的問題 25
3.3 偏振無感受架構 26
3.3.1 光路分析 26
3.3.2 偏振分析 27
3.4 感測系統的訊號解調 28
3.5 感測系統的訊號分析 30
3.5.1零點頻率與洩漏點的關係 30
3.5.2 延遲光纖長度與干涉訊號強度的關係 31
3.5.3 零點頻率-洩漏點的靈敏度探討 33
3.6 傳統架構的分析 33
3.6.1 零點頻率與洩漏點的關係 33
3.6.2 零點頻率-洩漏點的靈敏度探討 35
3.7 同軸式與傳統架構的比較 35
第四章 實驗步驟與結果
4.1 實驗架構 36
4.2 系統元件的特性量測 37
4.2.1 PZT特性的量測 37
4.2.2 光纖耦合器的量測 39
4.2.3 法拉第旋轉鏡的量測 39
4.2.4 光循環器的量測 40
4.3 感測系統的量測 40
4.3.1 洩漏點的量測 41
4.3.1.1 干涉訊號的量測 41
4.3.1.2 精確度的分析 42
4.3.1.3 零點頻率-洩漏點及其靈敏度關係 43
4.3.2 延遲光纖的量測 43
4.3.3 動態範圍的量測 44
4.4 傳統桑克干涉儀的量測 44
4.5 結果與討論 45
4.5.1 同軸式架構之優點 45
4.5.2 實際問題之探討 46
4.5.3 同軸式架構之缺點 47
第五章 結論與未來展望
5.1 結論 48
5.2 未來展望 48
參考文獻 50
附表 54
附圖 61
附錄A 89
附錄B 90
中英文對照表 95
作者簡歷 98

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