What is "spaser"

n. (context physics English) The nanoplasmonic counterpart of a laser; a nanoscale source of optical fields with potential uses in nanoscale lithography, probing and microscopy.

Spaser is a phenomenon that was first described by Bergman and Stockman in 2003. The name is an acronym for surface plasmon amplification by stimulated emission of radiation. The first such device was announced in August 2009, a 44- nanometer-diameter nanoparticle with a gold core surrounded by a dyed silica gain medium, created by researchers from Purdue, Norfolk State and Cornell universities.

The spaser is a proposed nanoscale source of optical fields that is being investigated in a number of leading laboratories around the world. If realized, spasers could find a wide range of applications, including nanoscale lithography, probing and microscopy.

From Nature Photonics:

Study of the quantum mechanical model of the spaser suggests that it should be possible to manufacture a spasing device analogous in function to the MOSFET transistor, but this has not yet been experimentally verified.

Nano-optics is now undergoing a period of explosive growth where new ideas, developments and impressive results appear on literally a daily basis. It is concerned with the science of concentrating optical energy into regions with subwavelength dimensions (typically tens of nanometres).