CAREER: Electric Field Localization and Enhancement at Optical Frequencies Enabled by Material's Dissipation

非技术描述：大多数材料吸收光，将电磁能转化为热能。传统上，对于光学材料的许多用途，能量耗散被认为是不希望的，需要最小化。主要的研究人员从一个新的角度来处理这个问题：通过将光学材料中的耗散转化为有用的功能来利用它。该项目实验研究了耗散光学材料构成的纳米光子结构中的电磁场约束和增强，并探索了其在分子传感中的应用。除了该项目的研究部分外，还开展了“思维风暴”研究生和本科生材料开发竞赛和高中生实验室沉浸活动，以加强批判性思维和解决问题的技能教育。技术描述：损耗直接影响材料周围电磁场的大小和相位的分布。由强吸收材料制成的光子结构可能会以类似于等离子体金属结构的方式诱导场重新分布。这一职业奖的研究部分探索了材料介电常数的虚部在控制光-物质相互作用中的新作用，特别是在有损耗/无损材料之间的界面上。主要研究人员利用光化学近场成像技术研究了有耗纳米结构中的电磁场增强，并实验测量了高度受限场的模体积。用电子能量损失谱研究了局域光子态密度。对这些纳米光子行为的理解可以导致新形式的表面增强拉曼光谱。大调谐范围内的复合材料研究和材料耗散的多功能动态控制研究为新型纳米光子器件的开发奠定了坚实的基础，改变了研究人员控制光、处理光学材料和设计光子结构的方式。

Non-technical Description: Most materials absorb light, converting electromagnetic energy into thermal energy. The energy dissipation has traditionally been considered as undesirable for many usages of optical materials and needs to be minimized. The principal investigator approaches this problem from a new perspective: to make use of the dissipation in optical materials by converting it into useful functionalities. The project experimentally investigates the electromagnetic field confinement and enhancement in nanophotonic structures made of dissipative optical materials and explores their applications in molecule sensing. In parallel with the research component of the project, "Thinkingstorm" graduate- and undergraduate-student competitions on materials development and a lab immersion activity for high school students are carried out to enhance the education of critical thinking and problem solving skills. Technical Description: Dissipative loss contributes directly to the distribution of both magnitude and phase of the electromagnetic field around a material. Photonic structures made of strongly absorbing materials may induce field redistribution in similar ways as plasmonic metal structures. The research component of this CAREER award explores new roles of imaginary part of material permittivity in controlling the light-matter interaction, especially at the interface between lossy/lossless materials. The principal investigator investigates electromagnetic field enhancement in lossy nanostructures using photochemical near-field imaging technique and experimentally measures the mode volume of the highly confined field. Electron energy loss spectroscopy is employed for studying the local photonic density of states. The understanding of these nanophotonic behaviors can lead to new forms of surface enhanced Raman spectroscopy. The research on composite materials over a large tunable range and on versatile dynamic control of material dissipation provides a solid base for new families of nanophotonic devices and changes the ways in which researchers control light, process optical materials, and design photonic structures.