[Under construction]2014 AFOSR MURIPlasma-Based Reconfigurable Photonic Crystals and MetamaterialsPO: Dr. Mitat Birkan, Space Propulsion and PowerPI: Dr. Mark Cappelli, Stanford UniversityWebsite: TBD
Metamaterials and photonic crystals are arrays of macroscopic material structures of combinations of dissimilar materials that resonate with or interfere with electromagnetic waves and are used, for example, to filter, focus, and steer electromagnetic radiation. By selection of appropriate materials properties, such as combinations of materials with negative permittivity and permeability, metamaterials and photonic crystals can also have a negative refractive index that can be used to construct “super-lenses”, which can focus radiation below the diffraction limits. A research program is described that focuses on the fundamental science necessary for the development of plasma-based metamaterials and plasma photonic crystals that operate in the mm-wave range of the electromagnetic spectrum. Such devices require relatively high electron densities, typically 1013 cm-3 – 1016 cm-3, to effectively interact with such high frequency electromagnetic waves. Plasmas afford the opportunity to add a new dimensionality to these engineered materials by providing a complex, anisotropic, and even negative refractive index, and by allowing “reconfigurability”, i.e., the rapid control of electromagnetic wave interactions at very high bandwidths. Interactions are particularly strong at plasma resonances and cut-offs, which can be tuned by control of plasma density and external magnetic fields. When integrated into two-dimensional and three-dimensional devices, high density plasmas will also interact with, and be affected by, their material surroundings, limiting life and performance. The desire to expand the operability of these devices into the THz range is also limited by resistive losses in the dielectric and metals. In this MURI, we have assembled a team to study: (a) the theoretical, computational, and experimental aspects of generating ordered magnetized and non-magnetized microplasmas of moderate to high densities needed for mm-wave interactions; (b) the control of these plasmas; (c) the plasma interactions with their metal and dielectric surroundings; (d) the development of new dielectric materials that afford lower losses at high frequencies and which might displace the use of metals in metamaterials, which have high losses at higher frequency; and (e) the integration of these plasmas into novel 2D and 3D devices.