具覆蓋層之矽基片B型抗諧振反射光波導環形共振感測器的設計、製作與特性量測

Abstract

本論文提出一種運用B型抗諧振反射光波導(ARROW-B)加覆蓋層之環形共振感測元件，論文中討論元件的設計、分析所運用的方法，以及元件的製作和特性量測。由於B型抗諧振反射光波導擁有較大的入射導光區，所以能夠有效和單模光纖相匹配。我們利用轉移矩陣法與等效折射係數法來分析與設計B型抗諧振反射光波導結構。我們在直波導上加氧化矽覆蓋層，使元件與環境的折射率差異更大。我們利用二維有限時域差分法來模擬分析光場在元件中的傳播特性，使其在水環境下具有最佳化的感測靈敏度。我們共設計了四種間隙，分別為0.2、0.4、0.6和0.8微米，所得到的靈敏度為306、329、320、307奈米/單位折射率。我們製作出具覆蓋層之B型抗諧振反射光波導環形共振感測元件並量測其特性，在間隙是0.4 與0.6微米的情況下，所量測到的靈敏度為162.8以及295.4奈米/單位折射率。

In this study, ring resonator sensors with capping layers based on the type B antiresonant reflecting optical waveguide (ARROW-B) structure are proposed. Design, analysis, fabrication, and characteristics of these devices have been investigated. The ARROW-B waveguide with a thicker guiding region provides efficient coupling with a single-mode fiber. We used the transfer matrix method and the effective index method to design and analyze the ARROW-B structure. We added capping layers (silicon oxide) on the bus waveguides to increase the refractive index difference between the device and the environment. We used the two-dimensional finite-difference time-domain (2D-FDTD) method to simulate and analyze the light propagation characteristics in our devices with the optimized sensitivity in an aqueous environment. We designed four kind of gaps which are 0.2, 0.4, 0.6, and 0.8 μm. The sensitivity is about 306, 329, 320, and 307 nm/RIU, respectively. The devices with capping layers were fabricated and characterized. The sensitivity of the fabricated ARROW-B ring resonator sensor was obtained as 162.8 and 295.4 nm/RIU for gap = 0.4 and 0.6 μm, respectively.