基于石墨烯的光子晶体慢光波导

发布时间：2018-06-22 23:23

本文选题：石墨烯 + 光子晶体波导　；参考：《浙江大学》2017年硕士论文

【摘要】：为了促进全光通信网络的发展,满足全光通信网络中的关键器件一全光缓存器一日益增长的需求,本文主要设计了基于石墨烯的等效光子晶体慢光波导,并对石墨烯慢光波导用于全光缓存进行了研究,本文主要完成了以下三方面的工作。首先,我们验证了石墨烯作为慢光材料的可行性,并且在石墨烯上构造了折射率周期变化的等效光子晶体宽带慢光波导,在此基础上使用平面波展开法仿真其能带曲线。我们提出了基于石墨烯的45度晶格光子晶体线缺陷慢光波导,在设定的材料参数和结构参数下,当入射波的频率f在29.9THzf30.6THz之间变化时,波导的平均群折射率维持在(137.2±4)左右,慢光的相对带宽达到2.31%,归一化延迟带宽积高达3.17。在此频率范围内群折射率可视为是一个常数值,呈现出慢光效应,实现了慢光的传输。此外,我们通过控制施加在石墨烯上的偏压可以有效地调节慢光的中心频率f,群折射率ng,慢光带宽等参数。第二,为了进一步研究耦合腔型的等效光子晶体慢光结构的特性,我们又设计了两种等效光子晶体耦合腔慢光结构-60度晶格耦合腔慢光结构和90度晶格耦合腔慢光结构。在60度晶格耦合腔波导中,当入射波的频率在29.62THz-30.02THz范围变化时,波导的群折射率保持在(177.5± 10)左右,归一化延迟带宽积达到2.38。在90度晶格耦合腔波导中,当入射波的频率在28.7THz-29.5THz范围变化时,波导的群折射率保持在(142.5±7.9)左右,归一化延迟带宽积高至3.92,极大地改善了慢光波导的性能。最后,我们详细地介绍了慢光缓存器的原理以及衡量慢光缓存器性能参数,并且将我们设计的三种慢光波导结构带入计算公式进行了定量地分析,通过理论计算和比较,90度晶格耦合腔慢光结构性能相对优异,缓存容量高达331.6比特,延时时间最长为475.00皮秒,比特长度最大为3.0微米。
[Abstract]:In order to promote the development of all-optical communication network and meet the increasing demand of all-optical buffer, an equivalent photonic crystal slow optical waveguide based on graphene is designed. The application of graphene slow optical waveguide to all optical buffer is studied. Firstly, we verify the feasibility of graphene as a slow light material, and construct an equivalent photonic crystal broadband slow optical waveguide with periodic refractive index variation on graphene. On this basis, the energy band curves are simulated by plane wave expansion method. We propose a 45 degree lattice photonic crystal line defect slow optical waveguide based on graphene. When the frequency of incident wave f varies between 29.9 THzf30.6 THz, the average group refractive index of the waveguide is maintained at (137.2 卤4) under the given material and structure parameters. The relative bandwidth of slow light is 2. 31 and the normalized delay bandwidth product is 3. 17. In this frequency range, the group refractive index can be regarded as a constant value, showing slow light effect and realizing the propagation of slow light. In addition, we can effectively adjust the central frequency of slow light, group refractive index, slow light bandwidth and so on by controlling the bias applied on graphene. Secondly, in order to further study the characteristics of the equivalent photonic crystal slow light structure of coupling cavity, we also design two kinds of equivalent photonic crystal coupling cavity slow light structure -60 degree lattice coupling cavity slow light structure and 90 degree lattice coupled cavity slow light structure. When the frequency of the incident wave changes in the range of 29.62THz-30.02THz, the group refractive index of the waveguide remains at (177.5 卤10) and the normalized delay bandwidth product reaches 2.38 in the 60-degree lattice coupled cavity waveguide. In a 90 degree lattice coupled cavity waveguide, when the frequency of the incident wave varies in the range of 28.7THz-29.5 THz, the group refractive index of the waveguide remains at (142.5 卤7.9), and the normalized delay bandwidth product is up to 3.92, which greatly improves the performance of the slow optical waveguide. Finally, we introduce the principle of slow light buffer and the performance parameters of slow light buffer in detail, and introduce three kinds of slow optical waveguide structure into the calculation formula to carry out quantitative analysis. By theoretical calculation and comparison, the lattice-coupled cavity has excellent performance, with a buffer capacity of up to 331.6 bits, a delay time of 475.00 picoseconds and a maximum bit length of 3.0 渭 m.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN252;TN929.1

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