高靈敏度光纖濾波器與高感度光纖光柵之開發及應用於量測穩態振動與暫態波傳之研究

The development of high sensitive fiber grating filter and sensor in the applications of displacement measurement for transient wave propagation

林柏睿(Bo-Ruei Lin)

指導教授 ： 馬劍清

國立臺灣大學/工學院/機械工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.01866

摘要

光纖光柵在應變量測上具有抗電磁性以及高靈敏度的特性，但發展至今在真正動態量測應用上仍然有困難，主要的問題在於光柵訊號解讀的速度與精確度。目前已開發的能量調變型光纖光柵感測器原理是利用布拉格光纖光柵作感測應變，長週期光柵在前端作能量調變，藉此解讀光柵受應力後波長的改變。此架構量測較大振動時非常理想，但在量測微小的動態波傳時由於能量過低的問題，便無法解讀光纖光柵受激振而產生的改變，本論文將嘗試利用一般短週期布拉格光纖光柵與傾斜式光纖光柵替代長週期光柵作能量調變，並且測量微小的振動，將量測範圍從微米級再往下探伸至奈米級。同時本論文探討感測光纖經氫氟酸經蝕刻過後，搭配新開發的能量調變系統，探討面內與面外運動耦合效應的問題，並與雷射都普勒振動儀的量測結果作比較，作穩態振動及暫態波傳的研究。

關鍵字

傾斜式光纖光柵 ； 短週期光纖光柵 ； 能量調變 ； 雷射都普勒振動儀 ； 穩態振動 ； 暫態波傳

並列摘要

In the measurement of strain field and temperature variation, fiber grating sensor detection technique has been widely used. It has many advantages, such as high sensitivity, low insertion loss, electromagnetic immunity and potentially low cost. The characteristics of fiber grating sensor in sensing static and low frequency response have been frequently reported in the literature. However, in the capability of sensing dynamic response for fiber grating sensor may need for further investigations. The main objective of this thesis is to establish the experimental measurement system based on the grating based fiber sensors to obtain the dynamic transient response of structures subjected to dynamic impact loadings.
In this thesis, the tilted fiber Bragg grating (TFBG) and normal fiber Bragg grating (FBG) are proposed as new filter to increase the sensitivity of the fiber grating sensor measuring system. We also provide a new gluing method, it can be used to perform the measurement of out-of-plane motion . The fiber grating sensing-system is used as a displacement sensor and measurement sensitivity is in the order of submicrometer. The etched fiber grating sensor is developed to analyze the in-plane and out-plane coupling effect in transient wave propagation. All the transient responses are simutaneously measured by Laser Doppler vibrometer (LDV), and the results are in excellent agreement with that obtained by fiber grating sensing system.

並列關鍵字

Tilted fiber Bragg grating ； Fiber Bragg grating ； LDV ； Etched fiber grating sensor ； Transient responses

參考文獻

[44] 葉耀文，(2004)，短週期光纖光柵在動態系統的量測與應用，國立台灣大學機械工程研究所碩士論文

[45] 許碩修，(2005)，能量調變型光纖光柵感測器在動態系統的實驗量測，國立台灣大學機械工程研究所碩士論文

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