黃升龍Huang, Sheng-Lung臺灣大學:光電工程學研究所楊牧翰Yang, Mu-HanMu-HanYang2010-07-012018-07-052010-07-012018-07-052009U0001-2807200921081600http://ntur.lib.ntu.edu.tw//handle/246246/188432光學同調斷層掃描術在具有高解析度，真時影像掃瞄和非侵入性等特生，未來在細胞等級的檢測具有很大的發展潛力。現在有很多寬頻光源應用於光學同調斷層掃描上，如superluminescent diode、鈦藍寶石鎖模雷射、 LED，熱鎢鹵素燈等等，這些光源的頻寬很寬，因此在光學同調斷層掃描上，有很高的縱向解析度。然而當考量到影像品質，光源的頻譜形狀就是一個重要因素。有些光源由於干涉訊號的side lobe影響，使得影像品質很差。此外為了得到高的訊雜比，一個方法是降低雜訊，另一個方法是提高光源功率。論文我們討論了製作雙纖衣摻鉻釔鋁石榴石作為光學同調掃描術的光源。我們製作雙纖衣摻鉻釔鋁石榴石頻寬有245 nm，縱向解析度達3.6 μm。為了提高訊雜比，我們利用雙向幫浦和在端面鍍放大自發輻射高反射膜，最佳化放大自發輻射功率，總輸出功率可達3.15 mW，此外，本論亦探討幫浦光極化時放大自發輻之影響。時我們亦投入了製作雙纖衣摻鈦藍寶石晶纖，目前我們可以成功生長出纖心尺寸48 μm的晶纖，放大自發輻射光的頻寬可達164 nm，以其用在光學同調斷層掃描，縱向解析度可達1.56 μm。Optical coherence tomography (OCT) will play an important role in the future due to the high resolution, real time imaging, and the noninvasive detection for human cell. There are many light sources beam applied to OCT such as superluminescent diode, mode-locked Ti:sapphire laser, LED, thermal tungsten halogen lamp, ect. Because of the broadband spectrum, all these sources have high axial resolution. Take image quality into account, the spectrum shape is an important factor. Some of these light sources suffer from poor image due to the side lobe of the point spread function. In addition, higher signal to noise ratio can support better image quality. To achieve higher signal to noise ratio, one way is to reduce the noise, and another way is to enhance the light source power. In this thesis, we report the fabrication of Cr4+:YAG double cladding fiber as the broadband light source for OCT. The bandwidth of Cr4+:YAG double cladding fiber is about 245 nm, the axial resolution for OCT system is 3.6 μm. We also optimize the output of ASE by dual pump set and ASE HR coating on the endface of fiber, in order to enhance the signal to noise ratio. A total output power of 3.15 mW was achieved. In addition, in this thesis, we discuss the polarization effect of pump light on ASE. We have also fabricated Ti:Sapphire double cladding fiber. So far, we can fabricate double cladding fiber with 48 μm core size. The bandwidth of ASE is 164 nm, which can be used for OCT with an axial resolution of 1.56 μm.致謝 i文摘要 iiibstract iv錄 v目錄 vii目錄 x一章 緒論 1二章 摻鉻釔鋁石榴石之寬頻光源 4.1 鉻離子光學及物理特性 4.2 摻鉻釔鋁石榴石及摻鈦藍寶石之晶體光纖生長 9三章 理論與分析 13.1 四能階系統的速率方程式 13.3 極化對基態與受激態吸收的影響 18.3.1 速率方程式 18.3.2 幫浦功率傳播變化方程式 20.3.3 不同幫浦極化對於放大自發輻射之影響 22.4 最佳化放大自發輻射光 23四章 實驗架構及結果與討論 27.1 樣品製備 27.1.1 晶纖切割 27.1.2 晶纖包覆 28.2 實驗架構與結果 33.2.1 正向幫浦 33.2.2 反向幫浦 44.2.3 雙向幫浦 46.2.4 雙向ASE之收集 49.3 討論 51.3.1 單向與雙向幫浦之比較 51.3.2 雙向ASE之收集 53五章 摻鈦藍寶石晶體光纖寬頻光源 54.1 簡介 54.2 鈦藍寶石光學與物理特性 56六章 結論與未來展望 71考文獻 732559241 bytesapplication/pdfen-US光學同調斷層掃瞄術雙纖衣摻鉻釔鋁石榴石晶纖寬頻光源摻鈦藍寶石晶體光纖雙向幫浦optical coherence tomographyCr4+:YAG double-clad fiberbroadband light sourceTi:sapphirecrystal fiberdual pumpthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/188432/1/ntu-98-R96941049-1.pdf