Researchers create laser the size of a virus particle

"The reason we can fabricate nano-lasers with sizes smaller than that allowed by diffraction is because we made the lasing cavity out of metal nanoparticle dimers -- structures with a 3-D 'bowtie' shape," Odom said.

These metal nanostructures support localized surface plasmons -- collective oscillations of electrons -- that have no fundamental size limits when it comes to confining light.

The use of the bowtie geometry has two significant benefits over previous work on plasmon lasers: (1) the bowtie structure provides a well-defined, electromagnetic hot spot in a nano-sized volume because of an antenna effect, and (2) the individual structure has only minimal metal "losses" because of its discrete geometry.

"Surprisingly, we also found that when arranged in an array, the 3-D bowtie resonators could emit light at specific angles according to the lattice parameters," Odom said.