利用自組裝光學同調斷層掃描儀研究微小折射率之變化

The study of small refractive index changes by self-assembled optical coherence tomography

邱昱銓(Yu-Cyuan Ciou)

指導教授 ： 卓聖芬

共同指導教授 ： 吳見明(Chien-Ming Wu)

健行科技大學/電資學院/電子工程所/碩士(2012年)

https://doi.org/10.6824/UCH.2012.00043

摘要

本研究是以光學同調斷層掃描儀之組裝及其應用（Optical coherence tomography，OCT）為研究主題。OCT的主要技術背景是源自於麥克森干涉儀並以該架構做為基礎而演進，其特色是以使用低同調特性之光源用來對樣本進行非侵入式之顯影。
研究中主要是使用自行架設的光學同調斷層掃描儀系統測量三種不同種類介質變化與折射率之間的關連性，實驗項目分別為: 固相--玻璃介質旋轉角對應微小距離量測；氣相--空間空氣密度對應折射率變化量；與液相--電光調變器對應外加電壓變化量測。
在這三種項目中各有不同的成果，首先在不同入射角度對於玻璃介質內距離微小變化，實驗中由角度0度至30度的推算距離總變化量為0.1um-120um的範圍內，由系統實際量測出在於角度5度及10度可以達到與推算值誤差小於2.5%的結果。接著還針對空間中空氣密度的改變對應折射率變化做量測，得到的結果也驗證了折射率與密度變化之間的相互關係，最後還進行電光調變器對應外加電壓改變的量測，其中雖無法直接量測到作用的相位差變化，但解析過後的訊號仍然可以得知外加電壓強度與折射率呈現了正比的作用關係。

關鍵字

光學同調斷層掃描 ； 超聲波 ； 醫療成像 ； 生物醫學 ； 低同調干涉

並列摘要

The study focused on the application of a self-assembled optical coherence tomography (OCT). OCT’s system setup was improved from the Michelson interferometer. The major difference between Michelson interferometer and OCT is that OCT uses lower coherence light source to achieve the non-invasive imaging on samples.
The following three types of experiments were completed using self-assembled optical coherence tomography system, including the measurement of glass medium’s thickness under different rotation angle, the relationship between air density and refractive index, and the association between liquid crystal and refractive index using electro-optic modulator. Firstly in the solid medium measurement experiment, the distance changes from incidence angle of 0 degrees to 30 degrees were within 0.1um-120 um. The results of the thickness measurement were agreed, within 2.5% error, with the calculation value in the incidence angle of 5 degrees to 10 degrees. In the second experiment, our results showed the correlation between air density and refractive index. In the final experiment, because of the tiny difference of refractive index, the optical path difference could not be directly measured. However, after signal analysis, a positive correlation was verified in this study.

並列關鍵字

optical coherent tomography ； ultrasound ； medical imaging ； biomedical ； low coherence interferometer

參考文獻

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