中文摘要
光模轉換器由於可直接耦合至單模光纖，降低封裝上的成本，因此在光電整合電路為一重要的元件。藉由漸變式波導的結構，光模轉換器可把光波導之橢圓形光模轉換成單模光纖匹配的模態，而不需考慮元件耦合至單模光纖的問題。然而光模轉換器之轉換效率受到漸變式波導結構、材料折射率、激發的光波長等因素，限制了光模轉換器的設計及製作。為了增強光模轉換器在製程上的可靠度，以電壓控制光模轉換器並整合電致光吸收調變器的結構被設計及製作。漸變式波導是選擇性底切蝕刻InGaAsP的量子井結構，而電致光吸收調變器的主動波導寬度為3.5μm，而漸變式波導寬度是1.7μm至3.5μm。而轉換之光波導(被動波導)寬度在8μm。藉由調變漸變式波導電壓，耦合效率在光波長1560~1570增強了2dB。而單邊光模轉換器整合光調變器插入損耗為-12dB，消光比在22dB。藉由計算波導光模態的fabry-perot模，折射率變化量大約在10-3，和以kramer- kronig 模型計算的折射率是相符合的。

Abstract
Optical spot-size converter (SSC) is an essential element in the opto-electronic integrated circuit because of its direct coupling to single-mode optical fiber, low-cost from the misalignment issue in package. By the tapered waveguide structure, SSC offers a capability to transfer an elliptical optical mode of optical waveguide to single-mode fiber matched mode, allowing the independence of device design from the coupling issue. However, the conversion efficiency of SSC is strongly reliant on tapered waveguide structure, material index, and also excitation wavelengths, restricting design and fabrication of SSC. In order to enhance the reliability on SSC fabrication, a voltage-controllable SSC integrated with electroabsorption modulator (EAM) is designed and fabricated. The tapered waveguide processing is based on the selective undercut wet-etching on InGaAsP-material system. The active waveguide width of EAM is 3.5μm, where the tapered waveguide widths is ranged from 1.7μm to 3.5μm. The transferred optical waveguide (passive waveguide) is 8μm wide. By adjusting the voltage of tapered waveguide, coupling efficiency is enhanced by 2dB from 1560nm to 1570nm. A reliable SSC-integrated EAM with -12dB of insertion loss, extinction ratio of 22dB is demonstrated. By extracting the index change from Fabry-Perot optical mode of waveguide, index variation from reverse bias is in the order of 10-3, consistent with the calculation based on Kramer-Kronig model.

目錄
目錄 2
誌謝 4
中文摘要 6
英文摘要 7
第一章緒論 8
1.1前言 8
1.2研究目的 9
1.3研究步驟 12
1.4論文架構 12
第二章理論基礎與基本模擬 13
2.1電致吸收調變器 13
2.2光模轉換耦合器 15
2.3折射率變化的計算 18
2.4 結論 21
第三章 理論計算與模擬 22
3.1有效折射率之計算 22
第四章 元件製作 26
4.1離子佈植 26
4.2主動區與漸變區P型電極與波導 28
4.3 N接觸層蝕刻及N型金屬蒸鍍 33
4.4 Mesa以及蒸鍍介電質SiO2 34
4.5 PMGI平坦化以及蒸鍍CPW-Line 35
第五章 量測結果與結論 40
5.1 元件電壓電流曲線 40
5.2光輸出與偏壓關係 41
5.3 fabry-perot折射率計算 45
5.3結果討論 47
參考文獻 48

參考文獻
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