What Is a Nanolaser?

A nanolaser has all the typical properties of a standard size laser, meaning that light is amplified through the stimulated emission of radiation. The primary difference with a nanolaser is the scale of both the mechanism and the light beam that is emitted. The prefix "nano" is derived from a Greek word meaning "dwarf." Accordingly, a nanolaser is much smaller than a standard laser, both in footprint and the beam emitted. In fact, most nanotechnologies are often tens or hundreds of times smaller than traditional technologies.

Nanolasers feature the ability to condense or confine the light beam emitted beyond the diffraction limit of light. As a scientific concept, the diffraction limit of light refers to the ability to confine light. At one time, scientists believed that light could be confined to a maximum of half its wavelength. Such limits were deemed the diffraction limit of light. Unlike traditional lasers, however, nanolasers are able to confine a light beam as much as 100 times smaller than half its wavelength.

Lasers operate via a complex relationship between visible light, photons and wavelengths. Optical resonators, the components used to manage feedback in a laser, are needed to create the oscillation of photons that is necessary for the laser to emit light. Prior to the development of nanolaser technologies, the minimum resonator size was thought to be half the laser light's wavelength. By using surface plasmons rather than photons, developers were able to reduce the size of the resonator required for nanolasers and thus create the world's smallest lasers.

The first working nanolaser was developed in 2003. Proposals and suggestions for nanolaser technologies began in the late 1950s, although initial miniature plasmon lasers proved impractical. Since 2003, numerous advancements and refinements in nanolaser technology have resulted in ever-shrinking sizes. As of 2011, the smallest nanolaser was known as a spaser, with the name being an acronym for “surface plasmon amplification by stimulated emission of radiation.”

Applications for these tiny lasers include computers, consumer electronics, medical applications and microscopes, just to name a few. Spasers, for example, have the capacity to be made small enough to fit inside a computer chip, allowing information processing via light versus electrons. Similar nanotechnologies using semiconductor lasers, collectively known as biomedical microdevices, have been developed. These nanolaser biomedical devices allow scientists to discern cancerous cells from healthy cells using nanotechnology.