"This is a promising device that can operate at terahertz frequencies; it is miniaturised using mainstream semiconductor foundry; and it is in the same form factor as current communication devices,” said PhD student Sameer Sonkusale. “It's only one building block, but it could help to start filling the THz gap."
Although there is significant interest in using the THz band of the electromagnetic spectrum, the band has been underused because of a lack of compact, on chip components, such as modulators, transmitters, and receivers.
According to the researchers, measurements show that the modulation cut off frequency of the modulator exceeded 14GHz and has the potential to work at frequencies more than 1THz. By contrast, cellular networks occupy bands that are much lower on the spectrum where the amount of data that can be transmitted is limited.
The device works through the interaction of confined THz waves in a novel slot waveguide with tuneable, 2D electron gas. The prototype device operated within the frequency band of 0.22 to 0.325THz, which was chosen because it corresponded to available experimental facilities.