本論文致力於光纖液體感測之研究，主要感測參數為液體溶液折射率、液體溫度、以及水位高度。首先介紹本論文主要使用的光纖光柵─斜打光柵、長週期光柵、以及布拉格光纖光柵，包含原理以及製作過程，斜打光柵以1584nm的相位光罩傾斜四度角有最明顯的纖衣模態頻譜。使用斜打光柵以及長週期光柵進行糖水溶液的折射率感測並且介紹感測原理，斜打光柵對於環境折射率的變化大約為3.178 nm/n，而線性度R^2值約為0.9981；長週期光柵實驗結果則為大約為-32.699 nm/n，線性度R^2約為0.9715。接著再以斜打光柵及長週期光柵進行液體溫度感測並介紹其感測原理，長週期光柵對於液體溫度變化結果為-0.36nm/℃，整體線性度R^2約為0.9857，斜打光柵則為0.0094nm/℃，線性度則為0.9966。整合長週期光柵以及斜打光柵之感測優點並且製作複合式感測體，同時感測液體折射率以及溫度兩種參數並且推導感測公式，使得兩光柵能夠互相校準。最後為水位高度感測實驗，以長週期光柵進行高精準度的水位感測並介紹其感測原理，結果為波長飄移量1.494 nm/cm，精準單位可以達到0.1cm，感測範圍2.1cm；以布拉格光纖光柵黏貼於複合式材料上製作水壓力計進行大範圍的水位感測，並且介紹線型光纖雷射感測系統及原理，感測結果為-0.00304nm/cm，精準度達到10cm，感測範圍130cm，只要藉由改變複合式材料的厚度便能改變此系統的精準度以及量測範圍。

This thesis presents research on liquid characteristics sensing system using fiber grating. The key sensing parameters are liquid solution refractive index, liquid temperature and liquid level. First of all the introduction of fiber gratings used in this thesis---tilted fiber Bragg grating (TFBG), long period fiber grating (LPFG) and fiber Bragg grating (FBG) is given; including the working principles and manufacturing process. Using 1584 nm phase mask and tilting four degrees to generate the best cladding modes. Using TFBG and LPFB to monitor the refractive index of sugar solution and the sensing principles are discussed. The variation and the R square of TFBG based sensors are 3.178 nm/n and 0.9981, respectively; the variation and the R square of LPFG based sensors are -32.699 nm/n and 0.9715, respectively. Next is using TFBG and LPFG to monitor the liquid temperature. The variation and the R square of LPFG based sensors are -0.36nm/℃ and 0.9857, individually; the variation and the R square of TFBG based sensors are 0.0094nm/℃ and 0.9966, respectively. The advantages of two different sensing heads are combined to sense variations of index and temperature at the same time so they can calibrate with each other. The last part is water level sensing experiment, which is using LPFG to carry out the accurate level sensing. The result is 1.494 nm/cm with up to 0.1cm accuracy, and the sensing range is 2.1 cm depth. Pasting the FBG on carbon fiber reinforced plastic (CFRP) to make a water pressure sensor in order to achieve a larger water level range sensing; and introducing the linear-cavity fiber laser sensing system at the same time. The result is -0.00304 nm/cm with up to 10 cm accuracy, and the sensing range is 130 cm depth. Changing the thickness of CFRP to adjust the sensing range and the accuracy of the sensing system is also studied.

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