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.
