Terahertz waves, electromagnetic frequencies between microwaves and optical light, can be practically harnessed because the energy strongly interacts with graphene. That’s the breakthrough achieved through a research partnership between the University of Geneva, the Federal Polytechnic School in Zurich and two Spanish research teams.
The scientists have made a graphene-based transistor adapted to terahertz waves. The accomplishment could lead to useful tools in medical imaging, telecommunications and even in detecting firearms at airports.
“As quoted in Azonano.com, lead researcher Alexey Kuzmenko of the University of Geneva’s Department of Quantum Matter Physics, says: ‘Terahertz waves are stopped by metals and are sensitive to plastics and organic matter. This could lead to more effective means of detecting firearms, drugs and explosives carried by individuals, and could perhaps serve as a tool to strengthen airport safety.’”
Until now the functional use of terahertz waves has been hindered by the absence of suitable devices and materials to control them and offer adequate power output. The “Tearahertz Gap” exists because current terahertz sources can only generate a few milliwatts of average power.
“Per Azonano.com, study first author Jean-Marie Poumirol says her team has overcome this challenge: ‘By combining the electrical field, which enables us to control the number of electrons in graphene and thus allows more or less light to pass through, with the magnetic field, which bends the electronic orbits, we have been able to control not just the intensity of the terahertz waves, but also their polarization.'”
“Poumirol adds: ‘Using a film of graphene associated with terahertz waves, we should be potentially able to send fully-secured information at speeds of about 10 to 100 times faster than with Wi-Fi or radio waves, and do it securely over short distances.’”