Many researchers are working towards the goal of advanced optoelectronics with capabilities similar to modern electronics, but with less energy consumption and greater speed. One of the obstacles to them though is the diffraction limit of light, which prevents light from being confined to an arbitrarily small size. Plasmonics allow a way around this limit and now researchers at Northwestern University have created a laser that uses plasmons to emit light while being the size of a virus.
Plasmons are an interesting quasiparticle formed by the coupling of an electron and a photon. This coupling allows the information of the photon to be confined to a size much smaller than the diffraction limit of the light. In fact, in theory plasmons can allow light to be confined to any small size, and this is what the researchers have taken advantage of for their laser. By precisely designing the lasing cavity within nanoparticles shaped like a bowtie, the researchers have reached the scale of a virus particle, which should be very useful for creating optoelectronics that push the boundaries of information processing and storage
While the scale of the lasers is very important for eventually integrating it into silicon-based devices, another key property is that the lasers operate at room temperature. Something else that may also prove useful is that when arranged in an array, the laser light could be emitted at specific angles, depending on the arrangement.