Thursday, 29 August, 2013
Speaker: Dr. Jon Camden, University of Tennessee- Knoxville
Title: "Application of STEM/EELS to Optical Plasmons and Surface Enhanced Nonlinear Spectroscopy"
The last decade has seen an explosion in the study of plasmonic materials, with current applications including surface-enhanced spectroscopy, imaging beyond the diffraction limit, solar energy harvesting, and ultrasensitive detection. Our group has been working to characterize the near-field enhancements encountered upon excitation of the localized surface plasmon resonance. Recently, electron energy loss spectroscopy (EELS) in the scanning transmission electron microscope (STEM) has emerged as a technique capable of mapping the energy and spatial distribution of localized surface plasmon modes in nanostructures. Several applications of STEM/EELS to optically driven plasmonic applications are presented.
The intersection of higher-order spectroscopies with the emerging field of plasmonics is an unexplored frontier; therefore, in a parallel effort we are exploring the ability of plasmonic nanostructures to drive nonlinear spectroscopies, such as hyper-Raman. Surface enhanced hyper-Raman scattering (SEHRS) demonstrates the ability to probe single molecules. It further provides a method to probe the properties of nonlinear chromophores. Such studies have highlighted the importance of non-Condon scattering and suggest new ways to optimize the nonlinear properties of molecules.
This seminar will not be web cast.