2009-10-08
Towards Broadband Plasmonics: Tuning Dispersion in Plasmonic Crystals
Surface plasmons are responsible for a variety of phenomena including nanoscale optical focusing, negative refraction, and surface enhanced Raman scattering. Their characteristic evanescent electromagnetic fields offer numerous opportunities for sub-diffraction imaging, optical cloaking, and labelfree molecular sensing. The selection of materials for applications, however, has been traditionally limited to the noble metals Au and Ag because there has been no side-by-side comparison of other materials. This talk will describe our recent progress on manipulating surface plasmons from ultraviolet to near-infrared wavelengths using plasmonic crystals made from 2D nanopyramidal arrays. A library of plasmon resonances was constructed in the form of dispersion diagrams for a series of unconventional and new composite plasmonic materials. These resonances could be tuned by controlling both intrinsic factors (unit cell shape, materials type) as well as extrinsic factors (excitation conditions, dielectric environment). Finally, we will discuss prospects for generating plasmonic crystals with reduced lattice symmetries as a means to achieve broadband coupling.
To read more about Prof. Odom's research, click here.