Nanoplasmonics deals with collectve electron excitations at the surfaces of metal nanostructures,called surface plasmons. The surface plasmons localize and nano-concentrate optical energy creating highly enhanced local fields. Nanoplasmonics has numerous applications in science, technology, biomedicine, environmental monitoring, and defense.

 There is an all-important need in active devices capable of generating and amplifying coherent  optical fields on the nanosale analogous to lasers and amplifiers of the conventional optics or transistors of microelectronics. Such an active  device is the spaser(surface plasmon amplification by stimulated  emission of radition), also called plasmonic nanolaser.

We will present a recent breakthrough in ultrasensitive detection of explosives using the spaser. Another recent breakbthrough to be presented is an application of the spaser as an ultrabright annolabel and an efficient theranostic agent in biomedicine.