Tiny lasers hold key to nano-circuitry

Researchers have created the tiniest laser since its invention nearly 50 years ago. Because the new device, called a 'spaser', is the first of its kind to emit visible light, it represents a critical component for possible future technologies based on 'nanophotonic circuitry. The color diagram (a) shows the nanolaser's design: a gold core surrounded by a glasslike shell filled with green dye. Scanning electron microscope images (b and c) show that the gold core and the thickness of the silica shell were about 14 nanometers and 15 nanometers, respectively. A simulation of the spaser (d) shows the device emitting visible light with a wavelength of 525 nanometers. (Photo: Birck Nanotechnology Center, Purdue University)