利用光分碼多工擷取技術之光纖式振動感測器

Optical vibration sensor using code-division multiple access system

吳崇豪(Chung-Hao Wu)

指導教授 ： 鄭旭志

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2010年)

https://doi.org/10.6827/NFU.2010.00042

摘要

本論文利用光分碼多重擷取系統應用於振動感測器上。在光分碼多重擷取系統裡每個光柵編/解碼器都有屬於自己的頻譜振幅編碼，不同布拉格光柵中心波長刻蝕於光纖上形成一個布拉格編/解碼光柵，並在每個編碼器裡布拉格編碼光柵與光循環器之間各加入一個振動感測器去擷取出待測物的振動信號，再經由星狀耦合器集結每個編碼器的光譜信號，進入到各自解碼器去擷取出正確的信息位址出來。這裡使用頻譜振幅編碼具有良好正交性，使解碼器可有效濾除其它編碼器光柵頻譜並降低多重干擾擷取，由實驗結果得到此感測器成功地得到不同直流馬達的振動訊號。光分碼多重擷取技術的振動感測器可用在機械振動檢測及橋樑強度檢測多工應用上等。

關鍵字

光分碼多工擷取技術 ； 光纖式振動感測器

並列摘要

In this paper, the optical code division multiple access (OCDMA) system is applied to the vibration sensors which test measure objects. Through the measurement object makes the unstable variation of frequency, we can get whether there are problems of damage or need to maintain immediately in it or not. First, in OCDMA, each fiber Bragg grating（FBG）encoder/ decoder has their own spectrum amplitude codes that on the optical fiber wavelength form a Bragg encoding/ decoding grating in different FBG center, and between each encoder and the optical circulator add a variation sensor for exploring the vibrating signal of the measurement objects. Then, combining spectrum signals of each encoder from the star coupler assembly gets into the respective decoder to get the correct information address. In this experiment, we use that the spectral-amplitude-coding（SAC）which is good orthogonal makes decoders effectively filter out other grating spectral of encoders and reduce multiple-access interference (MAI). According to the result of the experiment, the sensor obtains successfully the signals of vibration with the different direct current (DC) motors. Therefore, in OCDMA system the vibration sensor can be used in detection of the mechanical vibration and bridge strength, and so on.

並列關鍵字

code-division multiple access system ； Optical vibration sensor

參考文獻

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