The propagation of the terahertz waves in ionized gas in a magnetic field of 178 tesla. Credit: Forschungszentrum Jülich
Yet it has the potential for numerous applications. In Physical Review Letters, scientists at Jülich together with their international partners present a new concept that uses short-pulse lasers to expand the capabilities of terahertz sources currently being developed. An important part was played by calculations performed on Jülich's supercomputer JUQUEEN.
Using detailed simulations, the scientists showed how the wavelengths and polarization of the generated terahertz radiation can be controlled via a strong external magnetic field. In the electromagnetic spectrum, terahertz waves occupy a band between microwaves and infrared radiation. The range from 0.1 THz to 30 THz, the so-called "terahertz gap", sits right between electronics and optics and is therefore not accessible through conventional electric devices or optical sources such as antennas and lamps. However, its special properties make THz radiation interesting for a variety of reasons: on the one hand, it penetrates textiles and plastics, while on the other, it is absorbed by many materials in a characteristic manner. The application spectrum ranges from non-invasive early cancer screening to food controls and body scans as well as ultrafast wireless connections.