中文摘要

由於去除光纖中OH-離子的技術突破，使得光纖可使用頻寬拓展至1.3 μm~1.6μm，而目前常用的光纖放大器均無法一次涵蓋整個1.3 μm~1.6μm頻寬範圍。近年來，摻鉻光纖已被證實可有1.3 μm~1.6μm的寬頻螢光頻譜，故極具有發展超寬頻自發輻射放大光源的潛力。

在本論文中，我們首次提出利用抽絲塔的製程方式來進行摻鉻光纖之抽絲，其生長速度快，可以高達200 m/min，並且成功的抽出10 km的摻鉻光纖。其纖芯的直徑均勻，且可以小於10 μm。而其自發輻射頻譜中心波長約在1310 nm，3 dB頻寬高達300 nm，量測遠場所得到的發散角為17°×15°(全角)和標準單膜光纖的發散角16°×16°(全角)相近，與標準單膜光纖熔接的損耗小，且容易與寬頻的WDM耦合器做耦合，故適合於商業化的量產以及被應用在光通訊的系統上。

Abstract

The breakthrough technology in dry fiber fabrication has opened the possibility for using fiber bandwidths all the way from 1.3 to 1.6 μm. The fiber amplifier that is in common use can not fully cover the whole, which its range is from 1.3 to 1.6 μm. Recently, the Cr4+-doped fiber has shown a broadband emission from 1.3 to 1.6 μm. Therefore, it is eminently suitable for super-wideband optical source.

In this study, we first propose and fabricate a Cr4+-doped fiber by employing a commercial drawing-tower method, which has good core diameter uniformity, the growth speed is up to 200 m/min, and the core diameter is less than 10 μm. The central wavelength of the ASE spectrum is at 1310 nm, and a 3-dB bandwidth is 300 nm. The divergent angle of the Cr-doped fiber is 17 o × 15 o and it’s also similar to a single mode fiber of 16 o × 16 o. Low-loss fusion splice can readily be done with the standard single mode fiber, and is beneficial when integrated with the broadband WDM couplers. Therefore, it is good for commercial production and application to light wave systems.

目錄

中文摘要………………………………………………………………… i
英文摘要…………………………………………………………………ii
致謝……………………………………………………………………iii
目錄……………………………………………………………………iv
圖目錄…………………………………………………………………vi
表目錄…………………………………………………………………ix
第一章 绪論……………………………………………………………1
第二章 Cr4+:YAG晶體光纖的特性……………………………………7
2.1 Cr4+：YAG的晶體結構與特性…………………………7
2.2 Cr4+：YAG的能階模型與吸收及放射頻譜………… 12
第三章 Cr4+：YAG晶體光纖之製作…………………………………16
3.1 文獻探討……………………………………………… 16
3.2 抽絲塔製造Cr4+：YAG晶體光纖…………………… 19
3.2.1 Cr4+：YAG預型體製造…………………………19
3.2.2 商用抽絲塔介紹……………………………… 24
3.2.3 抽絲塔製程Cr4+：YAG晶體光纖之製程參數 33
第四章 Cr4+：YAG晶體光纖之量測………………………………… 38
4.1 Cr4+：YAG晶體光纖之自發輻射量測……………… 38
4.2 Cr4+：YAG晶體光纖之折射率量測………………… 45
4.3 Cr4+：YAG晶體光纖之傳輸損耗量測……………… 47
4.4 Cr4+：YAG晶體光纖之遠場量測…………………… 51
第五章 結論………………………………………………………… 53
參考文獻……………………………………………………………… 56




























圖目錄

第二章
圖2-1 Cr：YAG單一晶格結構圖……………………………… 9
圖2-2 Cr4+：YAG晶體之能階示意圖………………………… 12
圖2-3 Cr：YAG晶體於室溫之吸收譜線………………………14
圖2-4 Cr4+：YAG晶體於室溫之自發輻射譜線……………… 14

第三章
圖3-1 CZ法示意圖…………………………………………… 16
圖3-2 LHPG生長法示意圖……………………………………17
圖3-3 自動焰磨車床……………………………………………20
圖3-4 摻鉻晶棒套入石英管中…………………………………20
圖3-5 利用套管方式製作Cr4+：YAG預型體退火後的情形…21
圖3-6 Cr4+：YAG光纖預型體示意圖…………………………22
圖3-7 Cr4+：YAG光纖預型體實體照片…………………………23
圖3-8 商用抽絲塔示意圖………………………………………24
圖3-9 抽絲流程圖………………………………………………25
圖3-10 觀察預型體何時掉絲……………………………………26
圖3-11 剛開始掉絲的頭端………………………………………27
圖3-12 調整剛開始掉絲外徑滾輪………………………………27
圖3-13 眼膜………………………………………………………28
圖3-14 抽絲塔電腦控制面板……………………………………29
圖3-15 自動收絲軸………………………………………………29
圖3-16 自動導絲軸………………………………………………30
圖3-17 自動導絲後的光纖絲……………………………………30
圖3-18 抽絲塔控制面板…………………………………………31
圖3-19 光纖外徑監測面板………………………………………32
圖3-20 預型體因熱應力而斷裂…………………………………33
圖3-21 外徑突然變大的摻鉻光纖………………………………35
圖3-22 二次抽絲的光纖預型體…………………………………36
圖3-23 Cr4+：YAG晶體光纖端面圖……………………………37
圖3-24 Cr4+：YAG晶體光纖側面圖……………………………37

第四章
圖4-1 2-D螢光強度量測架構圖………………………………39
圖4-2 beam splitter特性……………………………………… 39
圖4-3 為所量得的Cr4+：YAG螢光映像………………………40
圖4-4 Cr4+：YAG光纖反射螢光頻譜………………………… 41
圖4-5 Cr：YAG光纖自發輻射頻譜量測架構…………………42
圖4-6 Cr4+：YAG光纖自發輻射頻譜(6.1 cm)…………………43
圖4-7 Cr4+：YAG光纖自發輻射頻譜(8.3 cm)…………………43
圖4-8 不同長度的Cr：YAG光纖吸收示意圖………………… 44
圖4-9 EXFO-NR9200照片…………………………………… 45
圖4-10 EXFO-NR9200量測原理示意圖……………………… 46
圖4-11 Cr4+：YAG光纖折射率………………………………… 47
圖4-12 傳輸損耗量測之架構圖…………………………………48
圖4-13 Cr4+：YAG光纖傳輸損耗………………………………50
圖4-14 Cr4+：YAG晶體光纖遠場量測架構…………………… 51
圖4-15 (a) Cr：YAG光纖的遠場強度分佈圖………………… 52
(b) 標準單膜光纖的遠場強度分佈圖………………… 52
















表目錄

第一章
表1-1 光放大器的種類………………………………………… 2

第二章
表2-1 鉻離子在不同基材的輻射及吸收頻譜………………… 8
表2-2 YAG晶體結構與原子位置……………………………… 9
表2-3 Cr：YAG的物理特性……………………………………10
表2-4 Cr：YAG的熱特性………………………………………11
表2-5 Cr：YAG的光學特性……………………………………11
表2-6 Cr4+：YAG之特性整理………………………………… 15

第三章
表3-1 LHPG法與抽絲塔法抽摻鉻光纖比較…………………19
表3-2 石英與Cr4+：YAG晶棒材料特性比較…………………35

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