CMOS製程相容之光纖與矽光子導線高效率耦合器之研究

Abstract

本篇論文介紹了許多最近以矽為基底的光子導線之發展。因此針對通訊波段，我們提出了一個緊密且高效能的光柵耦合器，可以將光纖內的訊號垂直打入，耦合至平面波導中。但問題在於光纖與光子導線的模態尺寸及形狀都差異過大。因此我們設計了一個長方形的光柵，除此之外，我們在整體光柵結構的一端設計了一個蝕刻溝槽 (trench)，使光耦合到光柵時可往單一方向耦合，抑制另一方向的耦合。我們使用模擬軟體R-Soft來模擬，並取用微基因演算法(micro-genetic algorithm) 進行最佳化設計。

This thesis presents recent approaches in the development of a Si-based waveguides system for submicrometer devices. A compact and efficient grating coupler for tilt-incident with respect to the vertical axis coupling between optical fibers and silicon photonic wires is proposed. One of the drawbacks of the high index contrast is the large mismatch in mode size and shape between fibers and silicon photonic wires. Hence, a perfectly vertical fiber coupling is achieved by using an asymmetric grating structure to suppress the second order Bragg reflection from the grating. We use R-Soft to simulate our approaches and micro-genetic algorithm to find the best solutions.