臺灣博碩士論文加值系統

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傾斜光柵，並把它埋入高折射率的波導核心中。除此之外，為了防止光纖的訊號反射回光纖中，我們也將光纖稍微傾斜打入波導中並分析最後的耦合效能。我們使用模擬軟體R-Soft來模擬許多前人所提出來的各種方法，並將結果與本篇論文所提出的架構比較，最後我們將試著找出此架構的最佳解。

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 slanted grating with a parallelogram shape is designed through the entire high-index waveguide core. Otherwise, the optical fiber is slightly tilted in order to prevent a reflection and its coupling efficiency will be analyzed. We use R-Soft to simulate various approaches and compare them with slanted grating, and finally we try to find the best solutions.

Index
Index I
List of figures Ⅲ
Abstract in Chinese V
Abstract VI
Chapter 1. Introduction 1
1.1. Integrated optics 1
1.2. Motivation 2
Chapter 2. Background 4
2.1. Optical Waveguide Principle 4
2.2. Planar Optical Waveguides 7
2.2.1. Slab waveguides 7
2.2.2. Rectangular Waveguides 9
2.3. Coupling between High Index Contrast Waveguides and Single Mode Fiber 12
2.4. Most Widely Researched Methods 13
2.5. Vertical coupling between fiber and grating 16
2.6. Relative Research to Vertical Grating Coupler 18
2.7. Simulation tools 21
2.7.1. Two-dimensional finite time domain (2-D FDTD) method 21
2.7.2. Perfectly matched layer 25
Chapter 3. Literature Review 27
3.1. Spot-Size Converter 28
3.1.1. Structure 28
3.1.2. Results 28
3.2. Bilevel Mode Converter 29
3.2.1. Structure 29
3.2.2. Results 30
3.3. Subwavelength Waveguide Grating Coupler 32
3.3.1. Structure 32
3.3.2. Results 34
3.4. Silicon-on-Insulator grating coupler based on a poly-silicon overlay 35
3.4.1. Structures 35
3.4.2. Results 36
3.5. Slanted grating couplers 38
3.5.1. Structures 38
3.5.2. Results 39
Chapter 4. Embedded Slanted Grating Coupler for Tilt-Incident Coupling 41
4.1. Introduction 41
4.2. Structure and simulation method 42
4.3. Analytical Model 44
4.4. Simulation results and Discussion 46
4.5. Comparison between normal-incident ESGC and tilt-incident ESGC 52
Chapter 5. Conclusion and Future Work 57
References 58

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