The role of metamaterials and plasmons for novel sensing applications
The past ten years have seen a tremendous acceleration in the exploration of metals for photonic applications. This exploration has been common to both the metamaterials and the plasmonics fields, which leverage the strong resonances of structured metals to produce desired electromagnetic response. However, the unique electromagnetic properties of metal components and composite materials come at a price: while a seemingly limitless palette of electromagnetic behavior can be coaxed out of carefully designed metal structures - negative refractive index and optical magnetism being two striking examples - material losses and dispersion place heavy constraints on the ultimate usability of these properties. Despite their drawbacks, metamaterials based on metals and plasmonic structures also exhibit unique phenomena that are distinct from other systems and materials. Both structures possess the capability to localize electromagnetic fields to regions much smaller than the wavelength of light, and to strongly enhance the local fields. This focusing of light naturally brings about an extreme sensitivity to the local environment, which can be used to implement sensing or modulation functionality. By exploiting the benefits of metals - field localization, field enhancement and sensitivity to local environment - while minimizing their disadvantages, we hope to develop an array of unique and competitive devices across the electromagnetic spectrum. In this talk we describe the amazing electromagnetic response that can be achieved in engineered metamaterial composites with metal inclusions, including negative index materials and the recently reported "invisibility" cloaks. © 2007 IEEE.