Researchers at MIT and the University of Waterloo have developed a high-power, portable version of a device called a quantum cascade laser, which can generate terahertz radiation outside of a laboratory setting. The laser could potentially be used in applications such as pinpointing skin cancer and detecting hidden explosives.
Until now, generation of terahertz radiation powerful enough to perform real-time imaging and fast spectral measurements required temperatures far below 200 kelvins (-100 degrees Fahrenheit) or lower. These temperatures could only be achieved with bulky equipment that limited the technology’s use to a laboratory setting. In a paper published in the journal Nature Photonics, MIT researchers report that their terahertz quantum cascade laser can function at temperatures of up to 250 K (-10 F), meaning that only a compact portable cooler is required.
Terahertz quantum cascade lasers, tiny chip-embedded semiconductor laser devices, were first invented in 2002, but adapting them to operate far above 200 K proved to be so difficult that many people in the field speculated that there was a fundamental physical reason preventing it.
With a high operating temperature, the researchers can finally put this in a compact portable system and take this breakthrough technology out of the laboratory,. This will enable portable terahertz imaging and spectral systems that will have an immediate impact on wide-ranging applications in medicine, biochemistry, security, and other areas.
In a medical setting, the new portable system, which includes a compact camera and detector and can operate anywhere with an electric outlet, could provide real-time imaging during regular skin-cancer screenings or even during surgical procedures to cut out skin cancer tissues. The cancer cells show up “very dramatically in terahertz” because they have higher water and blood concentrations than normal cells.
The technology could also be applied in many industries where the detection of foreign objects within a product is necessary to assure its safety and quality.
Detection of gases, drugs, and explosives could become especially sophisticated with the use of terahertz radiation. For example, compounds such as hydroxide, an ozone-destruction agent, have a special spectral “fingerprint” within the terahertz frequency rage, as do drugs and explosives.
News Source: MIT
