利用光学天线耦合光波进入波导的研究

发布时间：2018-01-19 04:30

本文关键词： 表面等离子体光学天线耦合效率波导　出处：《贵州大学》2015年硕士论文　论文类型：学位论文

【摘要】：在集成光学中,光波的研究主要归结为光的激发、传输、路由和转化。波导作为光波传输的重要载体,是集成光路构成的一种基本元器件。将自由空间中光波高效耦合进入波导是很重要的。常见的耦合方式有光栅耦合、棱镜耦合和天线耦合。为提高光波进入波导的耦合效率,本文主要研究光学天线将光波耦合进入亚波长波导。基于时域有限差分方法模拟光波与仿真结构的相互作用,主要研究内容如下:1.利用“H”形光学天线耦合自由空间中的光波进入金属双纳米线波导的研究。基于天线共振增强特性,设计“H”型纳米光学天线,将自由空间中光波耦合进入金属波导。利用时域有限差分方法模拟得到耦合效率并优化天线结构参数。在通信波段,“H”形天线比偶极子天线具有更高的耦合效率。2.光波从自由空间向亚波长波导结构的耦合研究。利用纳米天线共振,自由空间中的光波能够耦合进入波导。在天线下方添加反射层反射透过光波,提高入射光波的利用率,从而增加耦合效率。并利用3维时域有限差分方法模拟光波与金属结构的相互作用,优化结构参数。结果发现添加反射层能够提高光波的耦合效率,最大达27.8%。3.光波从介质波导向等离子波导的耦合研究。本文通过在介质波导与等离子波导的衔接处添加光学天线,利用天线近场增强补偿光波能量在结构突变处的损失。利用时域有限差分,优化天线结构参数,使光路阻抗达到最佳匹配,得到光波的最大耦合效率值为78.2%。
[Abstract]:In integrated optics, the research of optical wave is mainly attributed to the excitation, transmission, routing and transformation of light. Waveguide is an important carrier of optical wave transmission. It is very important to efficiently couple the light wave in the free space into the waveguide. The common coupling method is grating coupling. Prism coupling and antenna coupling. In order to improve the coupling efficiency of optical wave entering waveguide. In this paper, the coupling of optical waves into subwavelength waveguides by optical antennas is studied. The interaction between optical waves and simulation structures is simulated based on finite-difference time-domain (FDTD) method. The main research contents are as follows: 1. The study of using the "H" optical antenna to couple the light waves in the free space into the metal double nanowire waveguide. Based on the resonant enhancement characteristics of the antenna, the "H" type nanoscale optical antenna is designed. The coupling efficiency is obtained by the finite difference time domain (FDTD) method and the antenna structure parameters are optimized in the communication band. The coupling efficiency of "H" antenna is higher than that of dipole antenna. The coupling of light wave from free space to subwavelength waveguide is studied. The light waves in the free space can be coupled into the waveguide and the reflection layer is added under the antenna to reflect the light waves to improve the utilization rate of the incident light waves. In order to increase the coupling efficiency, the interaction between light wave and metal structure is simulated by using 3D finite-difference time-domain method, and the structural parameters are optimized. The results show that adding reflection layer can improve the coupling efficiency of light wave. The coupling of optical waves from dielectric waveguides to plasma waveguides is studied. In this paper, optical antennas are added at the junction between dielectric waveguides and plasma waveguides. The near-field enhancement of the antenna is used to compensate for the loss of light energy at the point of structural change. The structure parameters of the antenna are optimized by using finite-difference time-domain (FDTD) to achieve the optimal matching of the optical path impedance. The maximum coupling efficiency is 78.2.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN25

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