What's more, their ability to carry vast quantities of data could hold the key to faster wireless communications. Hence, academics are racing to design low-cost and compact THz sources to expand their field of applicability beyond the expensive passenger scanning apparatuses found in some airports.
Now, a team of researchers at the Power and Wide-band-gap Electronics Research Laboratory (POWERlab) from Ecole Polytechnique Federale de Lausanne (EPFL) has built a nanodevice capable of generating extremely high-power signals in just a few picoseconds, producing high-power THz waves.
The compact and inexpensive device described in the Nature journal under the paper title “Nanoplasma-enabled picosecond switches for ultrafast electronics” consists of two metal plates situated very close to one another, separated by a gap as small as 20nm. When a voltage is applied, electrons surge towards one of the plates, where they form a nanoplasma. Once the voltage reaches a certain threshold, the electrons are emitted almost instantly to the second plate. This rapid movement enabled by such fast switches creates a high-intensity pulse (with a spiking voltage from 10V to 100V) that produces high-frequency waves. In contrast, conventional electronic devices are only capable of switching at speeds of up to one volt per picosecond, too low to produce high-power THz waves.