中文摘要

近年來由於光通訊需求的快速成長，因而帶動了通訊用1.3 mm~1.6 mm波長雷射光源的發展，摻鉻釔鋁石榴石(Cr4+:YAG)固態雷射將相當有潛力滿足此超寬頻之需求，且固態雷射具有高品質輸出模態、壽命長、結構簡單、體積小諸優點，因此其潛力將不容忽視。

本論文採用小尺寸之晶體光纖做為雷射增益介質，在晶體的兩端鍍上光學薄膜做成共振腔，可大幅縮小固態雷射之體積，降低成本，簡化固態雷射架構，同時提高散熱效率。實驗採雷射加熱基座生長法生長晶體光纖，此法不僅可輕易生長出直徑極小之單晶，且生長速度快、耗能低、控制容易，既經濟又快速，且無坩鍋污染問題。利用此方法我們已能生長出直徑最小50 mm之Cr4+:YAG晶體光纖，藉由玻璃包覆技術可將晶體光纖纖心直徑縮小至11 mm，形成波導結構，並能夠於玻璃包覆外層加上銅鋁合金包覆來提高散熱效率，將此元件加以研磨、拋光、鍍膜即可製成Cr4+:YAG晶體光纖雷射。論文中也同時對晶體光纖中之Cr2O3與CaO摻雜濃度分佈、螢光與折射率分佈、以及傳輸損耗與吸收係數做了量測與分析，同時，本論文也針對所研製之晶體光纖雷射進行模擬，了解Cr4+:YAG晶體光纖雷射輸出與吸收係數、傳輸損耗、輸出耦合率、晶體光纖直徑、晶體邊界溫度間之關係。

Abstract

During the last decade, the fast-growing communication need has promoted the development of the wavelength of 1.3 mm~1.6 mm laser light source. The Cr4+ doped YAG solid-state laser has potential to meet this super wideband demand. In addition, solid state laser has the merits of high laser beam quality, long lifetime, compact, and simple structure.

In this thesis, crystal fiber was used as the laser gain medium, and coated with optical thin film at its end facets as the laser cavity. Using this configuration, the volume and cost of the laser can be appreciatively reduced, and the heat dissipation can be improved.

The laser-heated-pedestal-growth method was used to grow crystal fiber, which can obtain small diameter at very fast rate and accurate control. High quality Cr4+:YAG crystal fiber with the smallest diameter of 50 mm was grown. A glass-packaged technique clothes the crystal fiber with a core diameter as small as 11 mm. Outside the glass clad Cr4+:YAG crystal fiber, Al-Cu alloy was employed as the heat sink to improve heat dissipation. After grinding, polishing, and coating of this device, the Cr4+:YAG crystal fiber laser was fabricated. Some characteristics of Cr4+:YAG crystal fiber, such as the distribution of Cr2O3 and CaO doping concentration, fluorescence intensity, refraction index, propagation loss, and absorption coefficient were measured and analyzed. In the meanwhile, some simulations of the laser output power depending on the absorption coefficient, propagation loss, output coupling, crystal fiber diameter, and crystal boundary temperature were discussed.

目錄
中文摘要 i
英文摘要 ii
目錄 iii
圖目錄 iv
表目錄 vii
第一章 緒論 1
第二章 Cr4+:YAG晶體光纖雷射原理 5
2.1 晶體特性 5
2.2 電荷補償 15
2.3 能階模型 19
2.4 傳輸模態 23
2.5 腔內損耗 27
第三章 晶體生長與元件製作 32
3.1 生長方法與架構 32
3.2 晶體光纖之包覆 38
3.3 元件之研磨與拋光 50
第四章 Cr4+:YAG晶體光纖特性量測 59
4.1 摻雜離子濃度量測 59
4.2 折射率與螢光量測 65
4.3 傳輸損耗與吸收係數量測 71
第五章 雷射與數值分析 76
5.1 雷射共振腔 76
5.2 光學鍍膜 78
5.3 雷射架構與結果分析 81
5.4 雷射理論模擬 90
第六章 結論 102
參考文獻 105
中英對照表 110
附錄：Cr4+:YAG模擬程式 114

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