Plasmon Resonance Spectroscopy and Mode Coupling in Metallic Nanostructures Consisting of Nano Arcs or Nano Crescents

Using infrared spectroscopy the localized surface plasmon resonances of nanorods, nanoarcs and nanocrescents were investigated. The reflection/transmission spectra are rich with information regarding the fundamental and higher order modes, their dipole component polarization, and the impact that shape design and material design have on the frequency response. Using electron beam lithography and focused ion beam milling to control the relative position of the nanoscale objects in homodimers, heterodimers and tetramers, we have investigated the coupling of plasmons by the response of the system to near-infrared radiation. This information is utilized in the design of thin-film plasmonic metamaterials with engineered chiral and non-linear optic responses (chiroptic and NLO effects).