Plasmonics, nanoplasmonics, and SPASER’s

Plasma oscillations in a fluid of itinerant electrons or holes have attracted renewed attention following the emergence of composite media where nanometer-sized metal particles are embedded in a dielectric host, or nanometer-sized holes are punched in a thin metal film. This has led to the discovery of some new physical phenomena, e.g., enhanced light transmission (ELT) by very small holes, (i.e., smaller than the wavelength) and a nanometric device, known as SPASER that can amplify or generate coherent light whose wavelength is much larger than the size of the device. Some of these new phenomena are described and discussed.