Smallest Laser Ever May Herald the Future Of Electronic Devices
For decades, electronic devices have been shrinking, in accordance with Moore's Law. Now, as circuits reach the size of single atoms, progress begins to bump up against the physical limitations of matter. Enter the spaser. This new kind of laser produces a beam so small that it could someday form the foundation of circuits made of light, not electrical impulses. The spaser (surface plasmon laser) uses excited gold nanoparticles to produce a laser with a wavelength ten times smaller than that of visible light. The process, developed by Mikhail Noginov, a material scientist at Norfolk State University in Virginia, involves coating the gold nanoparticles in an organic dye. When light hits the dye, it transfers that energy to a special class of electrons (the surface plasmons in "spaser") on the gold particles. The plasmons then emit the laser-like light at an astoundingly small wavelength...