Electronically Tunable Metamaterials
Speaker: Harry Atwater, Caltech
Abstract: Progress in understanding resonant subwavelength structures has fueled an explosion of interest in fundamental processes and nanophotonic devices. The carrier density and optical properties of photonic nanostructures are typically fixed at the time of fabrication, but field effect tuning of the potential and carrier density enables the photonic dispersion to be altered, yielding new approaches to energy conversion and tunable radiative emission. While the emissivity is normally a fixed material-dependent quantity, modulation of the carrier density enables tuning of the complex dielectric function and the emissivity of infrared emitter, enabling modulation of radiative emission at constant temperature. We experimentally demonstrate tunable electronic control of blackbody emission frequency and intensity in graphene metasurfaces using field effect tuning of the graphene carrier density. We also describe designs for metasurfaces based on patch antenna arrays that allow field effect tunability of the reflection amplitude and phase of the incoming field.
Biosketch: Professor Atwater received his B. S., M. S. and Ph.D. degrees from the Massachusetts Institute of Technology respectively in 1981, 1983 and 1987. He held the IBM Postdoctoral Fellowship at Harvard University from 1987-88, and has been a member of the Caltech faculty since 1988.