【作者】 樊艳娜；

【导师】 蔡祥宝；

【作者基本信息】 南京邮电大学 ， 光学工程， 2012， 硕士

【摘要】 表面等离子体激元(Surface Plasmon Polaritons,SPPs)是束缚在金属/介质界面的一种电磁波模式,具有透射增强、亚波长局域等特点,使得在亚波长尺度的金属结构中对光场实现局域化和导波成为可能,从而为提高光子器件的集成度带来了新的契机。近几年,金属介质亚波长SPPs波导成为一个研究热点,被认为是实现光电纳米集成的主导技术。论文首先介绍SPPs基本理论,包括色散特性、特征参数、激发方式等相关物理机制,这是进行SPPs相关研究的理论基础;接着对金属Drude模型以及分析SPPs模场分布的FDTD数值计算方法做了详细介绍,这对进行SPPs器件研究具有重要意义。在此基础上,本文对以下问题作了重点研究:1.构造了金属三角形结构,利用FDTD方法模拟了光照射此结构激发SPPs的情况,观察并分析了SPPs的传播过程。2.研究了金属/介质界面SPPs的干涉理论,推导了金属三角形结构SPPs干涉相消条件,并在FDTD仿真实验中观察到了此干涉相消现象。3.在对SPPs激发和干涉理论深入研究的基础上,设计了基于三角形的光控光开关器件,利用信号光和调制光所激发的SPPs的干涉相消作用,实现了对光的控制。整个结构尺寸仅为1.8 m m′1m m ( x′z方向) ,消光比约为23 dB ,开光时间仅为0.9 fs。基于SPPs的光开关可以在小于衍射极限的亚波长范围内实现对光的控制功能,可应用于高速大容量的光纤通信系统中,是未来集成光器件的重要研究方向。更多还原

【Abstract】 Surface Plasmon Polaritons(SPPs)are a special kind of electromagnetic field, which are confined to the interface of metal and dielectric materials. With the properties of transmission enhancement, sub-wavelength localization, making the possibility of in subwavelength scale metal structures achieve light field localization and guided waves, so as to bring new opportunities to raise the level of integration of photonic devices. Recently, based on SPPs metal/dielectric subwavelength waveguides become one of hot issue researches, which is seen as one of the leading technology to intergrating optical and electronic devices in the future.In this thesis, we present the basic theory of SPPs, such as dispersion relations, characteristic parameters, SPPs stimulating method, related physical mechanism and so on. This is the theoretical basis about research of SPPs. Furthermore, we describe details of metal dispersion model and FDTD numerical calculation method which is used to analyze of SPPs mode field distribution. This is of great significance to investigate the properties of the SPPs-based devices.The main research work includes the following aspects:1.We designed the metal triangle structure, using FDTD method to analyzed the situation of the excitation and the propagation of SPPs when light illuminate the structure.2.We studied the theory of the interference of SPPs on the metal / dielectric surface and deduced metal triangle structure SPPs interference cancellation conditions. We observed this interference cancellation phenomenon in FDTD simulation experiments.3.On the basis of deeply study near-field excitation of SPPs and SPPs interference theory, we designed the optical switch device structures based on metal triangle. With interference cancellation of SPPs excited by the signal and the modulated light, we realized the control of light on or off. The entire structure size is only 1.8 m m′1 m m, extinction ratio of the optical switch is 23dB, and the switching time is up to 0.9 fs.SPPs-based optical switch can control light in subwavelength, and can be applied to high-speed large-capacity optical fiber communication system. So it is an important research direction in the field of integrated optics.更多还原