中文摘要光学信息系统有着电学系统不可比拟的优势，而光集成技术是未来光器件的主流发展方向。为了提高集成度，人们发展了硅光子学，但是硅基绝缘硅（SOI）波导的高折射率差造成了光纤与波导耦合时模斑失配的问题。光栅耦合器是解决这一问题的有效方案。中红外是一个对于光传感有着重要意义的波段。本论文研究了用于中红外波段（4μm~5μm） 的具有高耦合效率的带宽SOI 波导光栅耦合器。 为了提高光栅耦合器的耦合效率，可以从提高辐射光功率及其方向因子和模斑匹配程度两个方面对理论分析得出的初始结构进行优化，并利用本征模展开法数值模拟。最终，设计的增加底部反射层的光栅耦合器拥有 80.0%的耦合效率和370nm的 3dB 带宽；在此基础上，本论文提出了利用迟滞效应设计非均匀光栅耦合器的方法。6641
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 用于中红外波段的光栅耦合器研究+文献综述:http://www.751com.cn/tongxin/lunwen_4261.html