Collaborative research: Mid-IR Photonic Funnels: Coupling, emitting, and re-shaping mid-IR photons in the nano-world

材料科学、纳米技术、医疗保健和通信领域的进步都需要精确控制和理解光与纳米级物体的相互作用。不幸的是，被称为衍射极限的现象阻止了光聚焦到小于大约一半波长的区域。对于热（中红外）辐射，衍射极限尺度大约是5微米，比半导体电子元件、病毒和其他感兴趣的物体的10-100纳米尺寸大得多。在这项合作研究中，研究人员开发了新的结构，光子漏斗，消除了衍射极限，有效地引导了自由空间和纳米尺度区域之间的光信号。从理论上讲，研究人员开发了方程和计算机代码来模拟光通过漏斗的传播，以及放置在漏斗内或靠近漏斗的纳米级物体的光发射。在实验上，研究人员开发了制造漏斗的程序，集成了光发射器，并分析了光通过和从这些结构发出的传播。这些新型复合材料的探索和发展有可能为生物、电子和光学结构的高分辨率探测以及与这些结构的工程光学相互作用开辟新的途径。此外，调查人员计划针对高中和大学水平的学生开展推广和教育活动，以及人员交流和跨学科培训。这个合作项目旨在解决光-物质相互作用的基本限制之一，即衍射极限。研究小组利用最近开发的复合光学材料，其中含有高度掺杂的等离子体内含物，双曲超材料，并开发了用于设计，制造和分析具有双曲核心的锥形结构的工具，光子漏斗，在重要的中红外频率范围内。双曲材料的强介电各向异性推迟了漏斗内衍射极限的开始，从而使光在微纳米尺度之间传播。研究小组从理论上和实验上分析了光子漏斗内部和附近的光-物质相互作用。具体来说，该团队开发了理论工具，能够精确模拟从内部和近场产生的光，以及通过漏斗的光传播。与此同时，该团队开发了制造和表征程序，以精确控制漏斗的几何形状，并了解它们的光学响应。团队内部的协作反馈使新型材料平台的全面开发成为可能，为光操作提供了独特的机会。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Progress in the fields of materials science, nanotechnology, healthcare, and communications all require precise control and understanding of light interaction with nanoscale objects. Unfortunately, the phenomenon known as the diffraction limit prevents focusing of light to areas smaller than approximately half the wavelength of the light. For thermal (mid-infrared) radiation, the diffraction limit-scale is roughly five microns, much larger than 10-100’s-nanometer size of semiconductor electronic components, viruses, and other objects of interest. In this collaborative research the investigators develop novel structures, photonic funnels, that eliminate the diffraction limit and efficiently guide the optical signals between free space and nano-scale areas. Theoretically, the investigators develop equations and computer codes to model propagation of light through the funnels, as well as the emission of light by nanoscale objects positioned within, and in proximity to, the funnels. Experimentally, the researchers develop procedures to fabricate the funnels, integrate light emitters, and analyze light propagation through, and from, these structures. The exploration and development of these novel composite materials have the potential to open new avenues in high-resolution probing of biological, electronic, and optical structures, and in engineering optical interactions with these structures. In addition, the investigators plan for outreach and educational activities aimed at both high-school and college-level students, as well as personnel exchange and training across the disciplines.This collaborative project aims to address one of the fundamental limits of light-matter interaction, the diffraction limit. The research team utilizes recently developed composite optical materials with highly doped plasmonic inclusions, hyperbolic metamaterials, and develops tools for the design, fabrication, and analysis of conical structures with hyperbolic cores, photonic funnels, in the important mid-infrared frequency range. The strong dielectric anisotropy of hyperbolic materials postpones the onset of the diffraction limit inside the funnels and thus enables propagation of light between micro- and nano-scales. The research team analyzes, theoretically and experimentally, light-matter interaction inside, and in close proximity to, the photonic funnels. Specifically, the team develops theoretical tools capable of accurate modelling of light generation from within, and in the near field of, the funnels, as well as of light propagation through the funnels. In parallel, the team develops fabrication and characterization procedures to accurately control the geometry of the funnels and to understand their optical response. The collaborative feedback within the team enables comprehensive development of a novel material platform offering unique opportunities for light manipulation.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.