Researchers in Northwestern and Columbia Universities, created a nanolaser that can be used in the near future for the imaging of living tissue. 

Being very thin, “1/1000th the thickness of a single human hair”, and made mostly of glass, which is biocompatible, the nanolaser is able to fit in the tissue with ease. 

Besides the specificity of the shape, the nanolaser can “effectively deliver visible laser light at penetration depths accessible to longer wavelengths,” said Northwestern’s Teri Odom, who co-led the research. The nanolaser has to not only be able to emit longer wavelengths in order to penetrate deeper into the tissues, but also be able to emit shorter wavelengths that are needed in the tissue.

Other scientists have created small-sized nanolasers before, but they all needed ultraviolet light to power them. “This is bad because the unconventional environments in which people want to use small lasers are highly susceptible to damage from UV light and the excess heat generated by inefficient operation,” says P. James Schuck, an associate professor of mechanical engineering at Columbia.

The researchers at Columbia and Northwestern were able to solve the issue using photon upconversion. This process creates a pattern of absorbing two or more photons that leads to a shorter wavelength and higher energy than the original. The researchers were able to generate visible photons from infrared photons. 

Pictured above is photon upconversion

With all these benefits, the nanolaser can be used potentially to create different types of laser therapy in order to help alleviate neurological disorders, such as Alzheimer’s and Parkinson’s. Furthermore, it can also help diagnose diseases. As discovered in University of Arkansas, the laser can be used to heat up tumor cells to be detected through ultrasound.