Template-based Fabrication of Three-Dimensional Optical Metamaterials

超材料是由工程亚波长结构组成的人工介质，这使它们具有自然界中通常不存在的迷人的新电磁特性。它们可以用作高性能天线、完美吸收体、超级透镜、隐身装置等。与底层结构相关的响应波长是尺寸、形状、成分和晶格排列的函数。尽管在过去的10年里，将超材料的响应从微波频率范围转移到光频率范围已经取得了很大的进展，但在“超材料”成为用于光学应用的实用材料之前，仍然有许多挑战需要克服。该奖项将专注于研究一种廉价，可访问和大规模的制造过程，以构建三维光学超材料。该项目的成果将通过出版物传播给技术人员和普通受众，并纳入课堂教学。该项目将包括强大和持续的教育计划，涉及不同种族的本科生和地区K-12学生。 超材料结构将通过掠射角沉积和二维自组装方法相结合来制备。三维超材料，特别是手征超材料的新设计和制造，将在数值和实验两方面进行探索。研究团队将利用高性能电磁建模和先进的纳米结构和表征方法来创建和优化光学超材料的新型纳米结构。独特的光学超材料，如垂直排列的开口环阵列、瑞士辊阵列、单螺旋/双螺旋阵列等，并确定其制造条件。预期这些结构将在电磁光谱的近红外和可见光区域中表现出负折射率性质，并且螺旋结构将在近红外-可见光区域中表现出强的电磁手性。这些结构在电磁隐身、反隐身和超级透镜中的应用将在理论和实验上进行探索。

Metamaterials are artificial media composed of engineered sub-wavelength structures, which cause them to have fascinating new electromagnetic properties that are not usually found in nature. They could be used as high performance antennae, perfect absorbers, super-lenses, cloaking devices, etc. The response wavelengths associated with the underlying structures are a function of size, shape, composition and lattice arrangement. Although there has been great progress in shifting the response of metamaterials from the microwave frequency regime to the optical frequency regime over the past 10 years, there are still many challenges to overcome before "metamaterials" become practical materials for optical applications. This award will focus on studying an inexpensive, accessible, and large-scale fabrication process to construct three-dimensional optical metamaterials. Discoveries from this project will be disseminated to technical as well as general audiences through publications, and incorporated into classroom teaching. The project will include strong and sustained education programs involving both undergraduate students with diverse ethnicity and regional K-12 students. A metamaterial structure will be fabricated through the combination of glancing angle deposition and two-dimensional self-assembly methods. Novel design and fabrication of three-dimensional metamaterials, especially chiral metamaterials, will be explored both numerically and experimentally. The research team will take advantage of both high-performance electromagnetic modeling and advanced nanofabrication and characterization methods to create and optimize novel nano-architectures for optical metamaterials. Unique optical metamaterials, such as vertically aligned split ring arrays, Swiss roll arrays, and single helical/double helical arrays, etc., will be designed and their fabrication conditions will be determined. It is expected that these structures will demonstrate negative index properties in the near infrared and visible region of the electromagnetic spectrum, and that helical structures will exhibit strong electromagnetic chirality in the near infrared-visible region. The use of these structures in electromagnetic cloaking, anti-cloaking, and super-lenses will be explored both theoretically and experimentally.