Biography
Biography: Michael A Fiddy
Abstract
This presentation focuses on man-made composites or metamaterials which exploit resonant behavior in their constituent elements or meta-atoms to reduce the overall refractive index. We illustrate the potential use of such materials as index values drop below unity and approach zero in various applications as well as their use as a possible ink for nanoprinting which is one of our motivations. We have investigated distributions of nanoparticles of various seizes and concentrations made from transparent conducting oxides. Their scattering and coupling interactions provide an enhanced or resonant response that can lower the index of the bulk material. These interactions are not included in traditional effective medium models which typically underestimate the actual index values. Our particles of choice are aluminum-doped zinc oxide which can be grown with known concentrations of Al in order to control their plasma frequency or permittivity zero-crossing. Their sizes and concentrations can also be controlled. The polarization dependence of these media has been investigated and will be reported here. Also new simulations and experimental results will be shown.
