OP: Investigating High-K Modes in Metamaterial Structures

非技术描述：本项目研究超材料的特性——由导电和绝缘材料交替薄膜组成的层状结构。这些超材料的光学特性取决于导体和绝缘体的特性，以及层的结构细节。超材料改变了光的正常传播，使比波长小得多的物体成像和光的向后弯曲等效果成为可能。这个项目的首要目标是更好地理解这些影响，以及如何在新的应用中利用它们。首先，研究小组正在研究如何使用这些超材料将光聚焦到超小的点上，从而实现强光集中。其次，将吸收光的材料放入超材料中，以了解不寻常的光传播如何改变其特性。这种结构可以使环境气体监测的有效传感器成为可能。在夏季的几个月里，女本科生和一名高中实习生与研究小组一起工作，以帮助扩大代表性不足的群体对科学的参与。这项研究还被用来开发一个科学教育模块，在各种外联活动中提供给当地社区。技术描述：该项目的目标是了解和控制光通过红外双曲超材料（hmm）的传播。这些hmm包括通过分子束外延生长的掺杂和未掺杂半导体的交替层。这种方法使晶体hmm的生长具有低损耗、尖锐的界面、高横向均匀性、可调谐的光学特性和层厚度的原子控制。通过亚波长光栅的光传输是研究的第一个课题。近场成像用于检测极端亚波长聚焦和亚波长特征成像。第二个主题旨在将量子阱整合到HMM结构中。这使得通过量子阱子带间跃迁和HMM光学态之间的强耦合来调制结构的整体光学特性成为可能。本研究发展了基于设计半导体hmm的单片集成红外光学系统创建所需的基本理解。

Nontechnical description: This project addresses the properties of metamaterials - layered structures comprising alternating thin films of electrically conducting and insulating materials. The optical characteristics of these metamaterials depend on the properties of the conductor and the insulator, as well as the structural details of the layers. Metamaterials alter the normal propagation of light, enabling effects like imaging of objects much smaller than the wavelength and backwards bending of light. The overarching goal of this project is to better understand such effects and how they may be harnessed in novel applications. First, the research team is investigating how these metamaterials may be used to focus light into ultra small spots, to enable intense light concentration. Second, light absorbing materials are being placed inside the metamaterial to understand how the unusual light propagation alters their properties. Such structures may enable efficient sensors for environmental gas monitoring. During the summer months, female undergraduate students and a high school intern work together with the research group, to help broaden the participation of underrepresented groups in science. This research is also being used to develop a science education module, to be made available to the local community at various outreach events.Technical description: The goal of this project is to understand and control light propagation through infrared hyperbolic metamaterials (HMMs). These HMMs comprise alternating layers of doped and undoped semiconductors grown by molecular beam epitaxy. This method enables the growth of crystalline HMMs with low losses, sharp interfaces, high lateral uniformity, tunable optical properties, and atomic control over layer thickness. Light transmission through subwavelength gratings is the first topic of investigation. Near-field imaging is used to examine extreme subwavelength focusing and imaging of subwavelength features. The second topic aims to incorporate quantum wells into the HMM structure. This enables modulation of the overall optical properties of the structure via strong coupling between the quantum well intersubband transition and the HMM optical states. This research develops the fundamental understanding required for the creation of monolithically integrated infrared optical systems based on designer semiconductor HMMs.