基于亚波长结构的表面等离激元功能器件研究

发布时间：2018-04-29 18:11

本文选题：表面等离激元 + 金属—介质—金属波导　；参考：《桂林电子科技大学》2017年硕士论文

【摘要】：随着当前通信技术的飞速发展,人类社会对于器件的高速化、集成度以及小型化提出了更高的要求。但由于纳米级电子线路受到RC时间迟滞、热噪声等影响,已越来越满足不了当今时代信息传播的需要。而传统的光子器件虽比电子器件在传输带宽方面拥有不可比拟的优势,但由于其受到衍射极限的制约,很难在纳米量级的尺度上进行高度集成。因此近些年,一种新型的基于表面等离激元(surface plasmon polaritons,SPPs)的光子器件应运而生。SPPs是一种存在于金属/电介质界面的特殊表面波,其最显著的特点在于可突破衍射极限的制约,并可将电磁波能量局限在亚波长尺度范围内,因此受到国内外大量研究者的追捧,被认为可在新一代纳米集成光路中发挥出很多潜在的应用。本论文主要研究了两种不同类型的微纳光子功能器件:金属波导滤波器与等离子体超材料吸波器。重点针对金属-绝缘体-金属波导中SPPs波的传播特性,设计了具有不同结构的等离子体带阻、带通滤波器。并利用经典的金属/介质/金属三明治超材料结构,实现了单带吸波器向双带吸波器的转换。通过有限时域差分(FDTD)法对这些结构进行模拟仿真,本文的主要研究成果如下:1、系统研究了基于对称多齿状金属波导结构中的光学滤波特性。从相位延迟的角度出发,理论探讨了在双齿状结构中禁带与突起产生的原因。提出了一种对称多齿状结构的SPPs带阻滤波器,其禁带宽度与中心波长可以通过改变结构的相关参数而进行调节。这些结果可能为下一代高性能纳米等离子体集成光路提供有意义的应用。2、提出了一种新颖的非对称多齿状结构的双带阻滤波器,通过改变齿的个数可以调节这两个带阻的宽度。此外,本文利用一阶共振与二阶共振的混合影响,可在两个带阻之间形成一个狭窄的透射峰,其半高宽最小为7.5nm,这个透射峰在波长选择滤波器或者激光器等领域展现出了潜在的应用。并且本文也提供了一种有效的方法对这个透射峰的共振波长进行调节。3、提出了一种基于金属/介质/金属超材料结构的完美吸波器。通过改变上层被空气条带贯穿的金属膜的厚度,可以将单一带吸收转换为双带吸收,同时本文证实了这两个吸收带的产生机制是完全不同的。此外,本文也探讨了中间介质层的厚度与入射光偏振角度对此吸波器性能的影响,并因此提出了一种十字形的双带吸波器结构。在此结构中,两个吸收带的产生机制是完全相同的。
[Abstract]:With the rapid development of communication technology, the high speed, integration and miniaturization of devices are demanded by human society. However, due to the influence of RC time delay and thermal noise, nanoscale electronic circuits can not meet the needs of information transmission in modern times. Although the traditional photonic devices have incomparable advantages over electronic devices in terms of transmission bandwidth, it is difficult for them to be highly integrated on nanoscale scale because of the restriction of diffraction limit. Therefore, in recent years, a new type of photonic devices based on surface plasmon polaritons (SPPs) has emerged as a special surface wave which exists at the metal / dielectric interface. Its most remarkable feature is that it can break through the restriction of diffraction limit. The electromagnetic wave energy can be confined to the sub-wavelength scale, so it has been sought after by a large number of researchers at home and abroad, and is considered to be able to play a lot of potential applications in the new generation of nanoscale integrated optical path. In this thesis, two kinds of micro-and nano-photonic functional devices: metal waveguide filter and plasma supermaterial absorber are studied. Focusing on the propagation characteristics of SPPs waves in metal-insulator-metal waveguides, plasma band-stop and band-pass filters with different structures are designed. The conversion from single band absorber to double band absorber is realized by using the classical metal / dielectric / metal sandwich supermaterial structure. These structures are simulated by finite difference time domain (FDTD) method. The main research results are as follows: 1. The characteristics of optical filtering based on pairwise multi-toothed metal waveguide structures are systematically studied. From the angle of phase delay, the causes of bandgap and protuberance in double-toothed structures are discussed theoretically. A symmetrical multi-tooth SPPs band-stop filter is proposed. The bandgap and the center wavelength can be adjusted by changing the parameters of the structure. These results may provide a meaningful application for the next generation of high performance nanoplasma integrated optical path. A novel asymmetric multi-toothed dual-band-stop filter is proposed which can adjust the width of the two band-stoppers by changing the number of teeth. In addition, a narrow transmission peak can be formed between the two band-stops by the mixed effect of first-order resonance and second-order resonance. The minimum half-maximum width is 7.5 nm. This transmission peak shows potential applications in wavelength selective filters or lasers. Furthermore, an effective method to adjust the resonant wavelength of the transmission peak is provided, and a perfect absorber based on metal / dielectric / metal supermaterial structure is proposed. By changing the thickness of the metal film which is permeated by the air strip in the upper layer, the single band absorption can be converted into the double band absorption, and it is proved that the mechanism of the two absorption bands is completely different. In addition, the influence of the thickness of the intermediate dielectric layer and the polarization angle of the incident light on the performance of the absorber is also discussed, and a cross-shaped dual-band absorber structure is proposed. In this structure, the generation mechanism of the two absorption bands is identical.
【学位授予单位】：桂林电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN713

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