高頻面內光纖光柵感測器及其動態量測系統之開發與研究

The Development of the High Frequency In-plane FBG Sensor and Its Dynamic Measuring System

梁正言(Cheng-Yen Liang)

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(2007年)

https://doi.org/10.6342/NTU.2007.10536

摘要

光纖光柵在具有的優良機械性質、抗電磁干擾等優點，因此在光電與量測領域上，有著發展的潛力。
目前本實驗室所使用的能量調變型感測系統，是用長週期光纖光柵及FBG短週期光纖光柵當濾波器之用，前者利用其穿透頻譜，有著能量測數十微米量級大位移量的特色；後者則利用其反射頻譜，有高靈敏度與量測微小動態位移的特色；唯長週期光纖濾波器受限其穿透能量較低，FBG週期光纖光柵濾波器其能量大多穿透光柵，反射能量利用低，使得量測時高頻與微小振動因主要訊號與雜訊混雜而無法判別，因此本論文利用FBG短週期光纖光柵之穿透頻譜做濾波，期能提高其訊噪比(SNR)。
同時本論文主要以本實驗室開發之能量調變型感測器為基礎，以短週期光纖光柵穿透頻譜濾波之穿透光路，以及將光纖光柵感測器平貼和平拉於待測物之表面，配合本實驗室開發出面外垂直式光纖量測，希望能改善以往光纖量測系統僅能一維之量測，期望發展出高頻光纖光柵感測器與多維度、多點之動態量測系統，探討面內與面外運動耦合效應。另外，光纖光柵感測器加上Dynamic Signal Analyzer，作為動態掃頻系統之開發與應用，亦是本論文之研究方向與重點。

關鍵字

短週期光纖光柵 ； 穿透頻譜 ； 同步量測 ； 多維量測 ； 掃頻系統 ； 穩態振動 ； 動態系統 ； 暫態波傳

並列摘要

Recently, fiber Bragg gratings (FBG) have been applied to sense strain and temperature variation due to their high sensitivity, electromagnetic immunity and good engineering properties. Many papers have been demonstrated their performance in many engineering fields, including strain measurements in civil engineering and composite structures. However, these applications were used for static or low frequency measurements, high frequency dynamic measurement needed further study.
We have used the intensity-modulated FBG sensing system with long period fiber grating (LPG) filter to measure micro-measurand in only one direction. In order to increase the sensitivity and signal-to-noise ratio of the FBG system and to make simultaneous dynamic measurements in multiple directions at a single point, we develop high-frequency in-plane and the out-of-plane FBG sensors with transmitted spectra of FBG filters to measure out-of-plane and in-plane dynamic responses. Furthermore, we integrate the FBG sensing system with Dynamic Signal Analyzer to develop a dynamic signal system. All dynamic responses are measured simultaneously by the LDV system and strain gage. Results agree with those obtained from LDV and strain gage.
Key words : FBG sensing system, high frequency dynamic measurement, FBG filter, simultaneous dynamic measurements, multiple directions.

並列關鍵字

FBG sensing system ； high frequency dynamic measurement ； FBG ； simultaneous dynamic measurements ； in-plane ； out-of-plane

參考文獻

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

Anderson, D. Z., Mizrahi, V., Erdogan, T., and White, A. E., (1993) “Production of in-Fiber Gratings Using a Diffractive Optical Element,” Electronics Letters, 29(6), 566-568

Ball, G. A., and Morey, W. W., (1992) “Continuously Tunable Single-Mode Erbium Fiber Laser,” Optics Letters, 17(6), 420-422

Ball, G. A., and Morey, W. W., (1992) “Compression Tuned Single Frequency Bragg Grating Fiber Laser,” Optics Letters, 17(6), 420-422

Berthold, A., and Dändliker, R., (1988) “Determination of the Individual Strain-Optic Coefficients in Single-Mode Optical Fibers,” Journal of Lightwave Technology, 6(1), 17-20