SOI-AWG元件之設計與製作

Abstract

隨著網際網路的盛行造成頻寬的需求，而頻寬的大量需求促進技術由原本單波長訊號光源朝多個波長訊號演進。高密度分波多工系統使原本傳輸容量的方式改變，得以快速提昇傳輸容量，使頻寬的容量因此以倍數激增。高密度分波多工/解多工器三種濾波技術，其中以陣列波導光柵最容易達到多波道數與窄頻道間距的功能，所以本論文以絕緣層矽晶的光波導結構來設計和製作此陣列波導光柵元件。在本論文中，簡述三種高密度分波多工/解多工器濾波技術的工作原理和優缺點以及陣列波導光柵的基本特性分析，並利用可做3D運算的光波導數值模擬軟體BeamPROP輔助設計模擬元件的結果。在元件設計上，利用元件輸出入波導的寬度改變成錐狀波導結構的方式可降低耦合損耗。在元件製程上，我們製作8個波道數、頻道間距為0.8nm(100GHz)的SOI-AWG元件。由實驗結果驗證在元件線寬6.3μm的脊狀波導模態分佈有單模模態與理論模擬的是最吻合的，但在元件損耗與理論模擬有些微差距，最後我們針對元件損耗原因來分析和探討，發現元件的損耗主要是因製程上蝕刻元件表面側壁的粗糙度過大所引起的，如能對製程上來改善使元件表面側壁更平整，其元件的特性會更有某一程度上的提昇。

Dense wavelength division multiplexing (DWDM) technology promises transmission capacity and flexibility in next generation broad-band optical fiber telecommunication networks. In this paper we present our design and fabrication results of array waveguide grating (AWG) devices based on the Silicon-On-Insulator (SOI) fabrication technology, Compared to other fabrication technologies like the Silica-on-Silcon technology，the SOI technology has the advantages of low-cost and monolithic integratability. SOI is potential for making monolithic multi-wavelength optical receiver system including the wavelength demultiplexer, photodetectors, and electronic circuitry. We use the beam propagation method (BPM) to simulate and design 8-channel gaussian-type SOI-based AWG devices. We have successfully reduced the singlemode fiber coupling loss of AWG by using a simple laterlly tapered spotsize converter. We obtains the coupling loss was reduced about 1dB. To achieve a flattened passband, we design a structure with parabolic waveguide horns bwtween an input waveguide and an input slab waveguide. In fabrication, we have fabricated an SOI-based 100GHz-spaced 8-channel AWG demultiplexer on a 4-in wafer. The output near-field image of the single mode at width=6.3μm on the SOI rib waveguide was measure. Finally, we found the main origin of AWG loss is the interface sidewalls roughness, which is caused during the rib waveguide etching .