From Meta to Meso: Science and Applications of Metamaterials-Inspired Nanophotonics

Metamaterials are artificial electromagnetic materials exhibiting unusual optical responses that are difficult to elicit from naturally-occurring media. Those include negative refractive index, strong magneto-electric response, and highly asymmetric/non-reciprocal behaviors. Metamaterials and meta-surfaces represent a remarkably versatile platform for light manipulation, biological and chemical sensing, and nonlinear optics. Many of these applications rely on the resonant nature of metamaterials, which is the basis for extreme spectrally selective concentration of optical energy in the near field. In addition, metamaterial-based optical devices lend themselves to considerable miniaturization because of their sub-wavelength features. This additional advantage sets metamaterials apart from their predecessors, photonic crystals, which achieve spectral selectivity through their long-range periodicity. Remarkably, some of the most exciting applications and the most inspiring fundamental science can be found at what I would call a mesoscopic boundary between photonics crystals (wavelength-scaled periodic arrangements of simple building blocks) and traditional metamaterials (deeply sub-wavelength arrangements of highly sophisticated designer elements). This transition to metamaterials-inspired nanophotonics requires considerable rethinking of some of the most basic tenets of traditional metamaterials, such as collective effects, the role of optical retardation and nonlinearity, hybridization and strong coupling of nanoscale materials with photonic structures, integration of metasurfaces with microfluidic delivery systems, and the interaction of such structures with wavelength-size objects such as biological cells. I will illustrate these points using some of the examples from our group's recent work. The examples will include all-dielectric super-chiral metasurfaces, graphene-based modulators of infrared light, and photonic topological insulators capable of guiding light around sharply curved trajectories. The concluding remarks will address future directions of research, including nonlinear graphene photonics using metasurfaces, characterization/detection of circulating tumor cells, and the integration of inherently quantum objects with metamaterials.
Gennady Shvets is a Professor of Physics at The University of Texas at Austin. He received his PhD in Physics from MIT in 1995. He has been on the Physics faculty at the University of Texas at Austin since 2004. Previously he has held research positions at the Princeton Plasma Physics Laboratory and the Fermi National Accelerator Laboratory, and was on the faculty of the Illinois Institute of Technology. His research interests include nanophotonics, optical and microwave metamaterials and their applications (including bio-sensing, optoelectronic devices, and vacuum electronics), and plasma physics. He is the author or coauthor of more than 150 papers in refereed journals, including Science, Nature Physics, Nature Materials, Nature Photonics, Physical Review Letters, and Nano Letters. Dr. Shvets was a Department of Energy Postdoctoral Fellow in 1995-96. He was a recipient of the Presidential Early Career Award for Scientists and Engineers in 2000. He is a Fellow of the American Physical Society (APS) and Optical Society of America (OSA). His research is currently supported by various government agencies, including National Institute of Health, Department of Energy, National Science Foundation, Air Force Office of Scientific Research, and Office of Naval Research.

Professor Shvets is one of the pioneers in the emerging field of plasmonic metamaterials, especially in the infrared part of the spectrum. He and his colleagues were the first to experimentally implementing the concept of the Infrared Perfect Lens based on polaritonic materials (SiC), and the first to experimentally investigate optical properties of the so-called hyperbolic metamaterials that enable the propagation of sub-diffraction light waves. His group's theoretical research addressed some of the most basic questions in metamaterials, including bi-anisotropy, homogenization, and Fano resonances. His most recent work deals with the applications of metamaterials and plasmonics to infrared light harvesting, thermal signature camouflage, solar thermo-photovoltaics, biosensing and molecular fingerprinting of proteins and cells using metamaterial arrays, nanoscale lasers/"spasers", optical imaging with sub-diffraction resolution using nanoparticle labels, photonic topological insulators, graphene-based metamaterials, and electron beam-driven metamaterials. He is particularly interested in the integration of metamaterials and metasurfaces with various applications-specific platforms such as microfluidics, and in developing metamaterials-inspired devices that utilize non-traditional active, nonlinear, and low-loss materials such as graphene, silicon, and silicon carbide. Multiphysics modeling of electronic and optical behavior of such materials upon integration with plasmonic metamaterials using high-performance computing is another exciting challenge that his group is presently pursuing.