Latest Progress in Spasers

Nanoplasmonics deals with collective electron excitations at the surfaces of metal nanostructures, called surface plasmons. The surface plasmons localize and nano-concentrate optical energy creating highly enhanced local... [ view full abstract ]

Nanoplasmonics deals with collective 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 nanoscale 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 radiation), also called plasmonic nanolaser. We focus on the newest ideas and review the latest experimental progress in spasers, which presently generate in a wide optical spectrum from IR to UV. We will present a recent breakthrough in ultrasensitive detection, in particular, on sensing of explosives vapors using the spaser. Another recent breakthrough to be presented is an application of the spaser as an ultrabright nanolabel and an efficient theranostic (therapeutic and diagnostic) agent in biomedicine (cancer diagnostics and treatment).