矽基片抗諧振反射光波導與B型抗諧振反射光波導結構之光子晶體波導元件研究

Abstract

本論文研究矽基片上結合抗諧振反射光波導與B型抗諧振反射光波導結構之包含60度彎折、120度彎折、以及Y型分光光子晶體波導元件之設計、製作、與特性量測。此波導結構具有相對大尺寸的導光核心層，可有效與單模光纖耦合。為有效提升具寬頻之光傳輸效率，利用了簡單膠囊形狀之拓樸缺陷於光子晶體波導彎折處以及Y型接面處。與傳統拓樸(conventional topography)結構設計比較，此膠囊形缺陷(capsule-shaped defect)具有相對大的尺寸以及平滑的孔洞形狀，於微影與蝕刻製程當中，顯得較為容易，並且仍可維持與原先設計之孔洞形狀。三維有限時域差分法之頻譜分析，顯示所設計之結合抗諧振反射光波導與B型抗諧振反射光波導結構之彎折型光子晶體波導與Y型光子晶體分光元件能提供涵蓋C-band與L-band之有效寬頻光傳輸。所設計之波導元件於國家奈米元件實驗室與交大奈米中心使用標準半導體製程之機台製作。量測結果證實所製作大角度彎折與Y型分光之矽基片抗諧振反射光波導與B型抗諧振反射光波導結構之光子晶體波導元件可提供良好之光傳輸與分光能力。

The design, fabrication, and characterization of silicon-based (Si-based) photonic crystal waveguides (PCWs) based on antiresonant reflecting optical waveguide (ARROW) and type-B antiresonant reflecting optical waveguide (ARROW-B) structures with 60° bends, 120° bends, and Y-branch power splitters were investigated. These waveguide structures had relatively large core sizes suitable for efficient coupling with single-mode fibers. Simple capsule-shaped topography defects were designed in the photonic crystal (PC) bend corner and Y-junction region to increase the broad-band light transmission. Compared with the conventional topography design, this capsule-shaped defect has a relatively large defect size and a smooth hole shape, so it becomes much easier for the lithography and etching processes and can still maintain hole shapes as the original design. The 3D finite-difference time-domain (FDTD) spectrum analysis results show that all our designed ARROW, and ARROW-B PC bends, and Y-branch power splitters could provide efficient broadband transmissions covering the C-band and L-band. In the device fabrication process, we successfully fabricated designed waveguide devices by using the instruments compatible with standard semiconductor fabrication in the National Nano Device Laboratories (NDL) and Nano Facility Center (NFC) at National Chiao Tung University (NCTU). Measurement results show that our fabricated Si-based ARROW and ARROW-B PCWs with sharp bends and Y-branch structures could provide good light transmission and power-splitting ability.