片上集成波导以及波导功能器件研究

发布时间：2018-07-03 11:11

本文选题：片上集成光路 + SOI纳米线波导　；参考：《国防科学技术大学》2015年博士论文

【摘要】：集成光路是满足日益增长的光通信网络容量与解决高性能计算机电互连瓶颈的有效途径。本课题以片上集成光波导作为切入点,围绕新型片上集成波导功能器件开展了一系列原理结构设计,主要研究内容和研究成果如下。(1)探索了金属表面等离激元在SOI纳米线波导模式控制上的应用。SOI纳米线波导模式控制是集成光路的基础性课题,其在偏振分复用技术和多模空分复用技术中有巨大的应用前景。本课题在简要分析了SOI纳米线波导模式和金属表面等离激元的基本特性后,提出了利用硅/金属混合波导控制SOI纳米线波导的新方法。基于多模干涉原理,通过巧妙地设计硅/金属混合的本征场分布,用两种不同硅/金属混合波导分别实现了超紧凑的波导类TE偏振与类TM偏振转换器和类TE基模与类TE一阶模式转换器。数值仿真结果表明,偏振转换器的偏振消光比在波长1.55?m处达到26.5 dB,而转换长度仅需610 nm。类TE基模与类TE一阶模式转换器的转换长度仅需1.1?m,在波长1.55?m处的消光比达到30 dB。(2)改进了现有的石墨烯等离激元波导结构。在深入分析了石墨烯光学电导率,费米能级与偏振电压关系,以及石墨烯等离激元模式色散关系后,提出了介质装载型石墨烯等离激元波导结构。这种波导结构基于等效折射率约束,不需要对石墨烯进行刻蚀加工,也不需要对石墨烯进行局部掺杂,而且易于加工和集成,有望成为石墨烯等离激元光学的基础功能器件。论文研究了求解介质装载型石墨烯等离激元波导模式色散关系的等效折射率解析模型。讨论了该波导的模式截止条件,单模范围以及模式特性的可调性。在此基础上,进一步深入研究介质装载型石墨烯等离激元波导间的定向耦合特性,发现改变石墨烯费米能级能有效地调控波导间的定向耦合功率比,并基于此设计了中红外波段电可控光开关,开关比在波长10.5?m处达到了16 dB。(3)提出了用纳米条带腔增强石墨烯与可见到近红外光相互作用的新方法。纳米条带腔集波导与腔的优势于一身,石墨烯与纳米条带腔耦合系统既利用了腔的场增强效果,又保持了与波导集成的方便性。针对特定的应用,论文提出了一种简单的纳米条带腔设计方法,并用瞬态耦合模理论从原理上分析了石墨烯与纳米条带腔耦合系统可能的状态。对于输入和输出波导对称的结构,石墨烯的吸收率最多为50%;对于输入和输出波导不对称的结构,满足临界耦合条件时,石墨烯的理论吸收率可达100%。在理论分析的基础上,用输入和输出波导对称的结构实现了超紧凑的片上集成石墨烯电光调制器。仿真结果表明该电光调制器在波长1.55?m附近的调制幅度达到7 dB,而器件的长度仅为6.5?m。利用输入和输出波导不对称的结构,首次实现了片上集成石墨烯近似完美吸收体,并详细地讨论具体的设计方法。仿真结果表明石墨烯的吸收率达到了97%,而石墨烯的长度仅为1.7?m。
[Abstract]:Integrated optical path is an effective way to meet the increasing capacity of optical communication network and to solve the bottleneck of high performance computer electrical interconnection. In this subject, a series of principles and structures are designed around the new integrated waveguide functional devices. The main research content and research results are as follows. (1) explore gold. The application of.SOI nanowire waveguide mode control in SOI nanowire waveguide mode control is the basic subject of integrated optical path. It has great application prospects in the polarization division multiplexing and multimode space division multiplexing technology. This topic is a brief analysis of the SOI nanowire waveguide mode and the base of metal surface plasmon. After this, a new method of controlling SOI nanowire waveguide by silicon / metal hybrid waveguide is proposed. Based on the principle of multimode interference, the eigenfield distribution of silicon / metal mixture is designed ingeniously. The ultra compact waveguide like TE polarization and TM polarization converter and TE like TE like TE are realized by the clever design of the mixed waveguide distribution of silicon / metal. The numerical simulation results show that the polarization extinction ratio of the polarization converter reaches 26.5 dB at the wavelength 1.55? M, while the conversion length only needs 610 nm. class TE base mode and the class TE first order mode converter only 1.1? M, and the extinction ratio at the wavelength 1.55? M reaches 30 dB. (2) and improves the existing plasmon waveguide junction. After analyzing the relationship between the optical conductivity of graphene, the relation between the Fermi energy and the polarization voltage, and the dispersion relation of the plasmons, such as graphene, the structure of the dielectric loaded graphene is proposed. This waveguide structure is based on the equivalent refractive index constraint, and does not require etching of graphene, and no need for Shi Moxi. Local doping, and easy to be processed and integrated, is expected to be the basic functional device for the ionization of graphene and other polaritons. This paper studies the analytical model of the equivalent refractive index of the mode dispersion relation of the dielectric loaded plasmon waveguide mode, such as loaded graphene, and discusses the mode stop condition, the single mode range and the adjustable mode characteristics of the waveguide. On this basis, the directional coupling characteristics between the dielectric loaded graphene and other ionization waveguides are further studied. It is found that the change of the Fermi energy level of graphene can effectively control the directional coupling power ratio between the waveguides, and based on this, an electrically controlled optical switch in the middle infrared band is designed, and the switch ratio reaches 16 dB. (3) at the wavelength of 10.5? M. A new method of interaction between graphene enhanced graphene with nanoscale strip cavity and visible near infrared light. The advantages of nanoscale strip lumen waveguide and cavity are presented. The coupling system of graphene and nanoscale cavity is used both to use the field enhancement effect of the cavity and to maintain the convenience of integrating with the waveguide. The possible state of graphene and nanoscale coupling system is analyzed in principle with transient coupled mode theory. For the symmetric structure of the input and output waveguides, the absorption rate of graphene is up to 50%; for the asymmetric structure of the input and output waveguides, the principle of graphene is satisfied when the critical coupling condition is satisfied. On the basis of theoretical analysis, on the basis of theoretical analysis, the ultra compact integrated graphene electro-optical modulator is realized by the symmetrical structure of input and output waveguides. The simulation results show that the modulation amplitude of the electro-optical modulator reaches 7 dB near the wavelength of 1.55? M, while the length of the device is only 6.5? M. using the input and output waveguides asymmetry. For the first time, the perfect absorption of graphene is approximately perfect. The specific design method is discussed in detail. The simulation results show that the absorption rate of graphene is up to 97% and the length of graphene is only 1.7? M..
【学位授予单位】：国防科学技术大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN25

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