RUI: Optical Excitation of Nonradiating Nanosphere for Lossless Device

RUI：用于无损器件的非辐射纳米球的光激发

基本信息

批准号：
1809410
负责人：
Uttam Manna
金额：
$ 13.56万
依托单位：
Board of Trustees of Illinois State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1809410&HistoricalAwards=false
关键词：
RUI Optical Excitation Nonradiating Nanosphere

项目摘要

The ability of metal nanoparticles to confine light to a very small volume (down to a few tens of nanometer) has been developed into novel miniaturized optical and electronic devices. However, the high level of losses associated with the noble metals and heating have always been a challenge limiting the efficiency of optical devices. In this regard, there is a "new kid on the block", namely electrodynamic "anapole" mode (i.e. "without poles" in Greek), that can overcome these issues by minimizing the radiative loss. This proposal plans to explore anapole mode associated with high-index dielectric nanosphere (Silicon nanoparticles) that can act as a radiationless source and confine energy efficiently by minimizing the radiative loss. The knowledge gained from our research can potentially be translated into prototypes that can be developed into novel optical and photonic devices, such as nano-lasers, broadband photo-detectors, sensors, etc. Our research will also enhance the undergraduate education by providing undergraduate participation in cutting-edge experimental research, integration of research into the curriculum, and networking opportunities with external collaborators and scientists, which will help motivate our students to choose a STEM career path, including students from under-represented community. Resonant optical excitation of dielectric particles offers unique opportunities for future optical and nanophotonic devices because of their reduced dissipative losses and large resonant enhancement of both electric and magnetic near-fields. In this regard, the discovery of the electrodynamic "anapole mode" as a non-radiating source in high index dielectric materials provides a unique playground to realize new nanophotonic devices. Under specific conditions, the superposition of internal modes (magnetic and toroidal) of high-index dielectric nanostructures can generate non-radiating states, called "anapoles", that are free from radiative loss. Even though the study of non-radiating objects has been part of fundamental physics for a long time, the dynamic anapole corresponding to the time-varying oscillating charge-current distributions in the optical frequencies was only experimentally demonstrated in 2015. Since spherical geometry is not suitable for excitation of the anapole mode under plane wave illumination, excitation of anapole mode in the demonstrated structure relied on the design of a highly specialized structure (Si nanodisk). However, in spite of constructing the nanodisk for the specific anapole condition, the nanodisk was unable to produce an "ideal" anapole mode.Here, instead of specifically designed structures, we propose to excite the anapole mode in isotropic nanosphere. Since plane wave illumination is not suitable for anapole mode excitation in a nanosphere, we will exploit the polarization symmetry of cylindrical vector beam to excite "ideal" anapole mode in isotropic nanosphere. More specifically, we will use the radial electric field distribution and absence of magnetic field in the focal plane of the radially polarized cylindrical vector beam to excite the ideal anapole mode. Since the nature of the excitation would be responsible for generating the anapole mode, our approach would provide a simple, straightforward alternate path to excite anapole mode that has been predicted to give rise to enhanced nonlinear effects, nanolasers, ideal magnetic scattering, as well as extremely high Q-factor and near-field enhancements.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

金属纳米颗粒将光限制在很小的体积（降至几十纳米表）中的能力已发展为新型的微型光学和电子设备。但是，与贵金属和加热相关的高损失一直是限制光学设备效率的挑战。在这方面，有一个“障碍物上的新孩子”，即电动力“ Anapole”模式（即希腊语中没有极点），可以通过最大程度地减少辐射损失来克服这些问题。该提案计划探索与高索引介电纳米球（硅纳米颗粒）相关的Anapole模式，该模式可以充当无辐射来源，并通过最大程度地减少辐射损失来有效地局限能量。从我们的研究中获得的知识可能会被转化为原型，这些原型可以发展为新颖的光学和光子设备，例如纳米激光器，宽带照相机，传感器等。我们的研究还将通过提供高级研究的研究，以帮助我们的研究人员和网络的研究，并为培训培训提供了一定的研究，从而增强了本科教育，并提供了一位培训的培训，并将其融入了培训，并将其融入了培训，并将其融入了一位培训的机会，并提供了一位培训的机会。路径，包括来自代表性不足社区的学生。介电颗粒的谐振光激发为将来的光学和纳米光子设备提供了独特的机会，因为它们的耗散性损失减少以及电气和磁性近场的大量共振增强。在这方面，在高索引介电材料中发现电动动力“ Anapole模式”是一种非辐射来源，这为实现新的纳米光子设备提供了独特的操场。在特定条件下，高指数介电纳米结构的内部模式（磁性和环形）的叠加可以产生无辐射状态，称为“ anapoles”，这些状态没有辐射损失。 Even though the study of non-radiating objects has been part of fundamental physics for a long time, the dynamic anapole corresponding to the time-varying oscillating charge-current distributions in the optical frequencies was only experimentally demonstrated in 2015. Since spherical geometry is not suitable for excitation of the anapole mode under plane wave illumination, excitation of anapole mode in the demonstrated structure relied on the design of a highly specialized structure （si纳米虫）。但是，尽管为特定的Anapole条件构建了纳米虫，但纳米界仍无法产生“理想”的Anapole模式。在此，我们建议在各向同性纳米球中激发Anapole模式，而不是专门设计的结构。由于平面波照明不适合纳米球中的Anapole模式激发，因此我们将利用圆柱矢量束的极化对称性，以激发各向同性纳米球中的“理想” Anapole模式。更具体地说，我们将使用径向电场的分布和在径向极化圆柱矢量梁的焦平面中不存在磁场来激发理想的Anapole模式。由于激发的性质将负责产生Anapole模式，因此我们的方法将为激发Anapole模式提供简单，直截了当的替代途径，预计已预测，该模式会带来增强的非线性效应，纳米射击器，理想的磁散射，理想的磁散射，以及非常高的Q-factor和近距离的奖励，并通过nsf的基础来表现出nsf的基础奖励。更广泛的影响审查标准。