本篇論文為探討五氧化二鉭(Ta2O5)光波導之研究，我們選擇開發了五氧化二鉭，利用該材料擁有寬能隙、高非線性折射係數以及在可見光至紅外光區無吸收的特性，使之在非線性光波導應用有極大的潛力。然而，波導的色散補償與材料的熱光效應對線性與非線性元件的基本特性影響極大，故首先本論文透過馬赫-曾德爾調製器(MZI)光波導結構進行全波段的色散量測，在波導尺寸大小為700×400nm^2與700×700nm^2的結構下，測得Ta2O5波導元件的群折射係數，並獲得實驗推算的色散值分別為‒1300ps/km•nm、‒460ps/km•nm，實驗結果與商用模擬軟體相符。此外，我們使用環形共振腔結構進行Ta2O5熱光係數之研究，由於環腔對折射率變動相當敏感，當環境溫度從20℃升至40℃，其共振頻譜的中心波長由1543.430 nm紅移至1543.586 nm，故在考慮熱光效應以及熱膨脹效應下，我們成功地估算出Ta2O5材料熱光係數為6.8×10^-6/K，該數值較常見的矽(Si)小兩個數量級，根據我們的研究結果證實了Ta2O5在材料的熱穩定性、與熱不敏感特性對其發展分波多工器、濾波器，顯現極大的潛力。

Tantalum pentoxide (Ta2O5) of a large bandgap material has recently utilized to demonstrate nonlinear optical waveguide applications due to its superior linear and nonlinear optical properties, including low absorption loss coefficient in visible to infrared regions, high Kerr coefficients, and free of nonlinear absorption. In this work, we have successfully fabricated Ta2O5 based Mach-Zehnder interferometer (MZI) waveguide structures. The waveguide width is fixed as 700nm, and the waveguide height is varied from 400nm to 700nm, the chromatic dispersion is significantly tuned from normal dispersion to anomalous dispersion regions. In addition, the experimental results have been compared to that of simulated by using the commercial tools (RSoft, Beam propagation method). Moreover, the thermal-optical coefficient of Ta2O5 has been investigated experimentally by using a micro-ring resonator structure. Taking the advantage of index-sensitively property of ring resonator, the material with ultralow thermal-optical coefficient is easily to be measured and analyzed by using a ring waveguide structure. The central wavelength of micro-ring resonator is red-shifted from 1543.430 nm to 1543.586 nm when the substrate temperature increases from 20 to 40ºC. By considering the thermal-optical and thermal expansion effect of micro-ring resonator, the thermal-optical coefficient of Ta2O5 is estimated to be 6.8×10^-6/K at ~1550 nm. The thermal-optical coefficient of Ta2O5 is ten times of magnitude less than those of conventional III-V semiconductors, indicating that Ta2O5 supports the development of thermal-insensitive devices, such as sub-multiplexer and filter element.

中文審定書 i
英文審定書 ii
致謝 iii
摘要 iv
Abstract v
目錄 vi
圖次 ix
表次 xiii
第一章 緒論 1
1.1 五氧化二鉭材料回顧與應用 1
1.2 研究動機與目標 8
1.3 論文架構 9
第二章 以整合式五氧化二鉭馬赫-曾德爾調製器進行色度色散量測 10
2.1 前言 10
2.2 介紹 11
2.2.1 以馬赫-曾德爾調變器進行色度色散之操作原理 11
2.2.2 材料的光學特性 13
2.2.3 波導結構設計 15
2.3 五氧化二鉭馬赫-曾德爾調變器製備 18
2.3.1 薄膜沉積 20
2.3.2 熱退火(Annealing) 23
2.3.3 薄膜之光學特性 26
2.3.4 電子束微影(E-beam Lithography) 28
2.3.5 顯影 31
2.3.6 乾蝕刻(ICP-RIE) 33
2.3.7 電漿輔助化學氣相沉積(PECVD) 35
2.3.8 切割(Dicing) 36
2.3.9 研磨(Polishing) 38
2.4 元件量測與分析 39
2.4.1 馬赫-曾德爾干涉頻譜量測 42
2.4.2 波導群折射率及色度色散分析 43
2.4.3 波導結構與色度色散關係分析 46
2.5 結論 47
第三章 以微環形共振腔進行五氧化二鉭光波導熱光係數量測 48
3.1 介紹 48
3.2 元件製程與模擬 49
3.3 系統架設與操作原理 52
3.4 量測分析 56
3.4.1 變溫度下推算五氧化二鉭折射率變化與熱光係數 56
3.4.2 變溫之群折射率與等效折射率計算結果之比較 61
3.4.3 與矽波導之等效折射率計算結果之比較 63
3.4.4 變功率之量測結果 68
3.4.5 與矽波導量測結果之比較 70
3.5 結論 72
第四章 結論與未來工作 74
附錄 75
A.1 前言 75
A.2 元件設計與模擬 76
A.3 未來工作 80
參考文獻 81

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