Faezeh Tork-Ladani:

Title: Electrodynamics of fused plasmonic nanojunction

Abstract: Plasmonic nano-junctions are prominent for enhancing optical phenomena towards single molecule resolution. One example is plasmonic nano-dumbbell, which is particularly interesting for placing a molecule in the gap of the two nanosphere, where a huge field enhancement can bring the single molecule dynamics into measurable quantities. At the same time, analysis of the nano-junction is a challenging problem. Many mechanisms, such as thermal expansion upon laser illumination, can modify the shape of the junction, and consequently the near field behavior of the hot spot. In this contribution, we focus on fusing of the nano-junction into a neck between the two nanospheres. We perform COMSOL simulation to understand the electrodynamics of the fused dimer in comparison with the normal dimer. Rayleigh scattering and near field of the fused dimer provide useful insights about the nonlinear optical responses of a single molecule in the hot spot.

Alex Fast:

Title: Wide-field surface-enhanced CARS microscopy of cells

Abstract: We have previously demonstrated a total internal reflection, wide-field CARS microscope, where the signal is enhanced with the aid of a thin gold layer that supports surface plasmon polariton resonances. This surface-enhanced CARS microscope is capable of generating images of lipid structures in close proximity (<100 nm) to the glass substrate at excitation densities that are 4 orders of magnitude lower than in point-scanning CARS microscopy. In this contribution, we demonstrate its application to visualizing lipids in aqueous media, including imaging of cells, with unique surface-sensitive contrast that cannot be obtained with conventional CARS microscopy.