Other attributes
Nanolasers generate coherent light at nanoscale that can be used for quantum photonics, in vivo cellular imaging, solid-state lighting and fast three-dimensional sensing in smartphones. Coherence is a fixed relationship between the phase of waves in a beam of radiation of a single frequency. When the phase difference between the waves of two beams of light is constant, the two beams of light are coherent. Unlike incandescent light, a laser produces a beam where all the components have a fixed relationship to each other.
Nanolasers are more compact, faster and more power-efficient than conventional lasers. Nanolasers are fabricated in different architectures where metal nanostructures confine light on a scale approaching or surpassing the diffraction limit. Nanolaser devices are able to localize electromagnetic fields at optical frequencies simultaneously in frequency, time and space.
A nanolaser was built by a team of researchers at Northwester and Columbia Universities, co-led by Teri Odom and P. James Schuck in 2019 that was 50-150 nanometers thick, which is 1/1000th the thickness of a human hair. The nanolaser can fit and function inside living tissues with potential applications in disease biomarker sensing or for treatment of deep-brain neurological disorders such as epilepsy.
The nanolaser is mostly comprised of glass and can be excited at longer wavelengths of light and emit shorter wavelengths of light. This makes the device useful for bioimaging because longer wavelengths of light are needed for penetrating farther into tissues. The nanolaser system operates in confined spaces and uses quantum circuits and microprocessors for ultra-fast and low-power electronics. Yb3+/Er3+-co-doped upconverting nanoparticles were conformally coated on Ag nanopillar arrays. Odom and Schuck’s teams used photon upconversion where low-energy photons are absorbed and converted into one photon with higher energy. The team started with low-energy “bio-friendly” infrared photons and upconverted them to visible laser beams. The nanolaser is transparent but is able to generate visible photons when optically pumped with light at wavelengths that the human eye does not see.
