用于中红外波段的光栅耦合器研究+文献综述
关键词 集成光路 绝缘硅 中红外 光栅耦合器 本征模展开法
毕业设计说明书（论文）外文摘要
Title Mid-IR Grating Couplers for Silicon-on-Insulator Nanophotonic Circuits
Abstract
Optical information systems are much more superior to electronic systems
and integrated photonics is a dominant trend for photonic devices in the
future. In order to realize large-scale integration, silicon photonics is
developed. However, the high refractive index contrast of silicon-on
insulator (SOI) nanophotonic waveguides also results in a large mismatch
between a single-mode fiber mode and a SOI waveguide fundamental mode. A
grating coupler approach is thought to be an effective solution to the
problem. Mid-IR plays an important role in optical sensing. In this paper,
we discuss the mid-IR(4μm~5μm) grating coupler for SOI waveguides with
a high coupling efficiency and a large bandwidth.
The increase of the coupling efficiency could be carried out by two aspects.
One is to increase the optical power radiated and the directionality of
it, and another is to improve the matching between the fiber mode and the
waveguide mode. The initial structure derived from theoretical analysis
then could be optimized by the two aspects and be computed by the eigenmode
expansion technique. At last, the designed grating coupler with a bottom
reflector shows a coupling efficiency of 80% and a 3dB bandwidth of 370nm.
On the basis of this structure, we propose a nonuniform grating coupler
based on the lag effect for designing.
Keywords photonic integrated circuit silicon-on-insulator mid-IR
grating coupler eigenmode expansion
目 次
1 绪论 . 1
1.1 光集成与硅光子学 1
1.2 模斑匹配与光栅耦合 3
1.3 中红外波导与光纤 5
1.4 本论文主要内容与创新性 6
2 理论分析与数值模拟 . 7
2.1 耦合模理论 7
2.2 体电流法 11
2.3 本征模展开法 14
2.4 本章小结 15
3 中红外光栅耦合器设计 . 15
3.1 初始结构设计 15
3.2 简单优化 18
3.3 增加底部反射层 21
3.4 非均匀光栅耦合器初探 23
3.5 本章小结 24
4 容差分析 . 25
4.1 对准容差分析 25