【作者】 聂晶；

【导师】 刘文；

【作者基本信息】 华中科技大学 ， 光电信息工程， 2015， 博士

【摘要】 随着现代微纳制造工艺的发展和纳米光子学的兴起,在纳米尺寸对电磁波的操控以及相应的新颖光学效应和应用已经成为国内外研究热点,由此制造的纳米光子学功能器件具有体积小、集成度高、性能优异的特性,在未来大规模集成光路以及全光网络中有着良好的应用前景。本文基于纳米光子学近场光理论,突破经典衍射极限理论,在亚波长尺寸范围研究了电磁波在由金属电介质组成的单层平板和多层平板结构,单光栅和双光栅结构,不对称环境下的光栅结构,以及光子晶体波导和谐振腔结构中的传播形式和异常特性。在纳米光子学功能器件领域得到了以下新成果：研究平板型亚波长结构中的异常共振,设计出了一种电介质-金属-电介质-金属(IMIM)多层平板结构窄带吸收器,在传统的MIM结构外部添加一层电介质层,一方面将入射光更容易的耦合到金属电介质金属层(MIM)所构成的FP腔,另一方面提供额外的增益层,使得整个器件的吸收率大幅增加,可达吸收率高于95%,且带宽小于1.9%。提出了一个包含无缝金属平板和Si, SiO2电介质平板的混合三明治结构,它能够支持从可见光到近红外的超宽光谱透射,这种宽谱透射弱依赖于入射光的偏振态和入射角,同时当使用15nm厚的银金属板层时,整个结构的等效薄膜阻抗只有2Ω/sq,可以有效减小在器件工作期间可能出现的电压衰减和焦耳热量的产生,因此非常适用于对薄膜阻抗要求很高的太阳能电池和大面积平板显示领域。创新性的提出了在近红外波段基于双光栅复合结构的宽谱透射器,对于TM偏振入射光在1.9μm附近能够实现透射率高于85%,半高宽度高达64%的超宽谱透射。此外还研究发现了在不对称环境下的复合光栅结构的完美异常吸收现象,定性的分析了光栅的结构参数,光栅狭缝材料对该吸收现象的影响,并基于这种吸收特性,提出了一种线型完美吸收器件。设计并制造出了一种新型的光子晶体高集成的光谱探测器元器件,在200nm厚的硅基片上制造出光子晶体波导和谐振腔模型,在传输波长1520nm到1560nm的通信波长内,把光源的频谱信息一一对应于探测器中空间位置信息并以此分辨光谱,光谱分辨率可达1nm。通过改变相应的光子晶体波导和谐振腔的参数,可以制造出可见光到红外区域的光谱探测器器件,且与传统光栅光谱探测器相比,体积小,精确度高,集成度高,在未来大量的集成光子器件中有着广泛应用。更多还原

【Abstract】 With the development of modern nanofabrication and nanophotonics, the study of manipulating electromagnetic wave in the nano structure and nanophotonic effection and application become a hot subject in recent years. The new nanophotonic functional devices has a good prospect in future large scale photonic integrated circuit and all optical networks because of their high compact, high integration and perfect performance features.Based on nanophotonics near-field optical theory and breaking the classical diffraction limit theory, the electromagnetic wave propagation characteristic both in metallic-dielectric single layer and multilayer slabs, single and dual grating structures, photonic crystal waveguide and nanocavity are investigated. In the nanophotonics devices field the following novel progress were gained:An ultra-narrow-band visible light absorber based on a stack of silver and alumina slabs is investigated. Due to the Fabry-Perot resonance supported in the alumina slab of the insulator-metal-insulator-metal structure and the silver’s inherent loss, an ultra-narrow-band absorption is realized in the visible region. The top insulator layer acting as a functional gain layer that can greatly enhance the injection efficiency of incident light with frequency falls into the gain bands. We discuss this problem and propose an impeccable IMIM structure that can greatly enhance the peak absorbance to95%, and the FWHM remain less than1.9%.A category of microstructure is proposed, which consists of a seamless metallic film sandwiched in multi-layer dielectric films of Si and SiO2. Such a structure can support unimaginable high broadband electromagnetic transmission from visible to near infrared. The transfer matrix theory is used to perform the numerical experiment and analyze the transmission characteristics. It has been revealed that Fabry-Perot and bulk plasmon resonant modes excited in the composite structure contribute to the high broadband transmission that is weakly dependent on the geometry parameters and the polarization and incident angle of the light. When using a15nm Ag film, the calculated structure’s sheet resistance is2Ω/sq, which is superior to that of indium tin oxide glasses, thus making promising applications in optoelectronic devices, especially in photovoltaics.Moreover we present a new mechanism to realize broadband transmission at near infrared in a dual-layer metallic-silver-grating structure. With parameters optimized, high transmittance up to85%with full-width-at-half-maximum bandwidth of64%near1.9m can be realized for TM-polarized light. And furthermore we predict an unexpected perfect optical absorption phenomenon of oblique-incident transverse magnetic polarized light in a metallic grating situated in asymmetric surroundings. The influences of structural parameters, such as grating thickness, slits material on the anomalous absorption are investigated. Based on these properties, a plasmonic absorption device with a designed absorption line shape is proposed.We demonstrate an infrared spectrometer based on a combination of line-defect waveguide and photonic crystal waveguide and nanocavity structure are fabricated on a200nm thick silicon membrane. This photonic crystal pattern having a resolution of1nm and operation bandwidth from1520to1560nm can be packaged into a microspectrometer when integrated with a two-dimensional detector array. And with substitution of membrane material and structure parameters, this design can be easily extended into the visible regime and developed for a variety of highly efficient, miniature nanophotonic applications.更多还原