A new breakthrough has brightened the scope of expanding the utilization of the terahertz band of frequencies for faster and wider data transmission.
Lying between infrared light and radio waves, terahertz band was facing under-utilization because of the nonavailability of compact, on-chip components such as transmitters, receivers, and modulators.
The innovation from Tufts University School of Engineering in Massachusetts had researchers developing a modulator that is high-speed, chip-sized, and requires no DC power supply, The highlight is it exceeds 14 gigahertz and can work above 1 terahertz (THz) on the electromagnetic spectrum.
This has opened up the scope for new generation wireless devices that can transmit terahertz frequencies with data transmission at unprecedented speeds compared to the present level.
The fabrication of the on-chip device capable of gigahertz-rate amplitude modulation has reasons to excite the industry.
The study has been published in Scientific Reports.
Highlights Of Modulator
"A prototype device is fabricated which shows THz intensity modulation of 96% at 0.25 THz carrier frequency with low insertion loss and device length as small as 100 microns. The demonstrated modulation cutoff frequency exceeds 14 GHz indicating the potential for the high-speed modulation of terahertz waves. The entire device operates at room temperature with low drive voltage (<2 V) and zero DC power consumption," the researchers said.
Bandwidth Crunch
Right now, most Wi-Fi and cellular networks are working with microwave frequencies of around one gigahertz. Moving to higher terahertz frequencies with high-speed data rates of 100 Gbit/s will be a big opportunity considering the rising bandwidth crunch.
"This is a very promising device that can operate at terahertz frequencies, is miniaturized using mainstream semiconductor foundry, and is in the same form factor as current communication devices. It's only one building block, but it could help to start filling the THz gap," noted, Sameer Sonkusale, corresponding author from Nano Lab, Department of Electrical and Computer Engineering, Tufts University.
The modulation cutoff frequency higher than 14 gigahertz and the potential to work above 1 THz will be a boon for cellular networks that are trying out the bands at the lower end of the spectrum and struggling with data transmission.
During the experiments, the prototype device operated within the frequency band of 0.22-0.325 THz, in accordance with the experimental facilities available though it can work in other bands as well.
The experiment has raised the bar of success rate when the past efforts to make terahertz modulators are factored in. In the past, engineers could push the limit only to a few kilohertz.
Areas Of Application
The experiment remains a harbinger for faster yet compact terahertz modulators that can deliver high data rate wireless communication, given the high carrier frequency of THz waves that will support signal bandwidth compared to the radio frequency (RF) bands currently in use.
The upcoming area of applications includes material identification, imaging, wireless communications, chemical and biological sensing.
For better optimization of terahertz communications, researchers are now experimenting with other components such as bi-dimensional superlattice materials that can accelerate electron oscillations in the terahertz range and also for new power splitters with unique waveguide architectures to enable transmission of wireless terahertz waves through existing fiber optic networks.
