**Seminars begin at 4:00 PM and will be held in Clark Hall Room 101**
September 23, 2016
Metal nanostructures concentrate optical fields into highly confined, nanoscale volumes that can be exploited in a wide range of applications. However, metal nanoparticles exhibit broad localized surface plasmon resonances that increase in width as the particle size increases. One way to narrow these broad responses is to organize the nanoparticles into arrays with spacings on the order of hundreds of nanometers. This talk will describe new ways to design arrays of strongly coupled nanoparticles that can exhibit extraordinary properties including programmable and reconfigurable modes and real-time plasmon nanoscale lasing. We performed detailed modeling to understand the near-field coupling responsible for these amplified lightmatter interactions. First, we will describe a new type of nanocavity based on arrays of metal nanoparticles that support lattice plasmon modes that can be amplified and that can result in room-temperature lasing with directional beam emission. Second, we will describe a new way to achieve ultra-narrow resonances via superlattice plasmons, collective excitations that are supported by hierarchical nanoparticle arrays. Finally, we will discuss how ultra-narrow resonances can be achieved and manipulated in emerging plasmon materials.