RUI: Unraveling Novel Nanophotonic Effects in Mid-Index Micro-Sized Dielectric Materials

RUI：揭示中折射率微米介电材料中的新型纳米光子效应

• 批准号: 2208240
• 负责人: Uttam Manna
• 金额: $ 28.82万
• 依托单位: Board of Trustees of Illinois State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2208240&HistoricalAwards=false
• 关键词: RUI; Unraveling; Novel; Nanophotonic; Effects

NON-TECHNICAL SUMMARY:When light interacts with matter, a number of things can happen – it can be absorbed, reflected, scattered, or transmitted. If matter has nanoscale features, light-matter interactions can lead to interesting phenomena. For example, optical anapoles can confine light energy within the volume of nanostructures. In the case of zero back scattering (ZBS), light is preferentially scattered in the forward direction. The emerging field of nanophotonics puts such phenomena to use in applications such as solar energy, imaging, medicine, optical communications, and data storage. However, observation of these novel nanophotonic effects is currently restricted to materials with a high refractive index, such as silicon and germanium, and requires features sizes on the nanometer scale. The research team at Illinois State University (ISU) plans to demonstrate these effects in mid-index materials, such as titanium dioxide and diamond, with micrometer scale features. This research will push the boundary in terms of availability of materials and their size well beyond the current limit for observation of these novel nanophotonic effects. In the long run, the knowledge gained from the team’s research could be used to develop more efficient optical and photonic devices, such as photodetectors and nanolasers. The PI will work to broaden the workforce in optics and photonics by training undergraduate students in research and integrating the results of this research project into the physics curriculum. Participation of underrepresented minorities in STEM will be encouraged by using existing ISU infrastructure to recruit and train underrepresented students, including outreach to local high school students.TECHNICAL SUMMARY:Resonant optical excitation of high refractive-index dielectric particles offers unique opportunities to demonstrate novel nanophotonic effects such as nonradiating anapole states, optimum forward scattering, and magnetic hotspot enhanced Purcell effects. These novel nanophotonic effects observed are related to the excitation of single dipolar modes in high-index lossless dielectric materials. These effects are inaccessible for microscale objects due to the contributions from higher order multipolar modes under plane wave illumination. Hence, observation of nanophotonic effects is currently restricted to a few relatively high-index materials in the limit of nanometer size – typically within silicon and germanium. It was recently theoretically predicted that one can unravel dipolar regimes in homogenous high-index spheres with a wide range of size parameter and refractive indices under illumination. The research team at Illinois State University (ISU) plans to experimentally unravel the dipolar regime, excite non-radiating anapole states, and demonstrate zero backscattering in mid-index (1.5 n 3.0) dielectric spheres in the micrometer range under illumination with tightly focused Gaussian beams (TFGBs). TFGBs selectively excite a few relevant Mie coefficients and control the relative weight of the different multipolar modes of the incident field. This approach will enable the investigators to unravel the dipolar regime and associated novel nanophotonic effects in microscale homogenous spheres in the mid-index regime. Understanding these phenomena opens up enormous possibilities in terms of availability of materials and objects with size parameters well beyond the current physical picture for related nanophotonic applications.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.

当光与物质相互作用时，会发生许多事情-它可以被吸收，反射，散射或透射。如果物质具有纳米尺度的特征，光与物质的相互作用可能会导致有趣的现象。例如，光学纳普尔可以将光能限制在纳米结构的体积内。在零反向散射（ZBS）的情况下，光优先在前向方向上散射。新兴的纳米光子学领域将这种现象应用于太阳能、成像、医学、光通信和数据存储等领域。然而，这些新的纳米光子效应的观察目前仅限于具有高折射率的材料，如硅和锗，并且需要纳米尺度的特征尺寸。伊利诺斯州州立大学（ISU）的研究小组计划在中等折射率材料（如二氧化钛和金刚石）中展示这些效应，并具有微米级特征。这项研究将推动材料的可用性和它们的尺寸远远超出目前观察这些新的纳米光子效应的限制。从长远来看，从该团队的研究中获得的知识可以用于开发更有效的光学和光子器件，如光电探测器和纳米激光器。PI将致力于通过培训本科生进行研究并将该研究项目的结果整合到物理课程中来扩大光学和光子学的劳动力。通过利用现有的ISU基础设施招募和培训代表性不足的学生，包括推广到当地高中生，鼓励代表性不足的少数民族参与STEM，技术摘要：高折射率介电粒子的共振光激发提供了独特的机会，以展示新颖的纳米光子效应，如nonradiating anapole状态，最佳前向散射，磁热点增强珀塞尔效应。观察到的这些新的纳米光子效应与高折射率无损介电材料中的单偶极模的激发有关。这些影响是不可访问的微尺度物体由于在平面波照明下的高阶多极模式的贡献。因此，纳米光子效应的观察目前仅限于纳米尺寸极限内的一些相对高折射率的材料-通常在硅和锗内。最近理论上预测，可以解开偶极制度在均匀的高折射率球的尺寸参数和折射率在照明下的范围很广。伊利诺伊州州立大学（ISU）的研究小组计划通过实验解开偶极机制，激发非辐射anapole状态，并在紧聚焦高斯光束（TFGB）照射下在微米范围内证明中等折射率（1.5 n 3.0）介电球体中的零后向散射。TFGB选择性地激发一些相关的米氏系数，并控制入射场的不同多极模式的相对权重。这种方法将使研究人员能够解开偶极制度和相关的新的纳米光子效应在中等折射率制度的微米级均匀球体。了解这些现象开辟了巨大的可能性，在材料和物体的可用性方面的尺寸参数远远超出了当前的物理图片相关nanophotonic application.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。