Wi-Fi and cellular data traffic are increasing exponentially but, unless the capacity of wireless links can be increased, all that traffic is bound to lead to unacceptable bottlenecks.
Upcoming 5G networks are a temporary fix but not a long-term solution. For that, researchers have focused on terahertz frequencies, the submillimeter wavelengths of the electromagnetic spectrum. Data traveling at terahertz frequencies could move hundreds of times faster than today’s wireless.
In 2017, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) discovered that an infrared frequency comb in a quantum cascade laser could offer a new way to generate terahertz frequencies. Now, those researchers have uncovered a new phenomenon of quantum cascade laser frequency combs, which would allow these devices to act as integrated transmitters or receivers that can efficiently encode information.
The research is published in Optica.
“This work represents a complete paradigm shift for the way a laser can be operated,” said Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering and senior author of the paper. “This new phenomenon transforms a laser — a device operating at optical frequencies — into an advanced modulator at microwave frequencies, which has a technological significance for efficient use of bandwidth in communication systems.”
This work represents a complete paradigm shift for the way a laser can be operated.
Frequency combs are widely-used, high-precision tools for measuring and detecting different frequencies — a.k.a. colors — of light. Unlike conventional lasers, which emit a single frequency, these lasers emit multiple frequencies simultaneously, evenly spaced to resemble the teeth of a comb. Today, optical frequency combs are used for everything from measuring the fingerprints of specific molecules to detecting distant exoplanets.
This research, however, wasn’t interested in the optical output of the laser.
“We were interested in what was going on inside the laser, in the laser’s electron skeleton,” said Marco Piccardo, a postdoctoral fellow at SEAS and first author of the paper. “We showed, for the first time, that a laser at optical wavelengths can operate as a microwave device.”
Inside the laser, the different frequencies of light beat together to generate microwave radiation. The researchers discovered that light inside the cavity of the laser causes electrons to oscillate at microwave frequencies — which are within the communications spectrum. These oscillations can be externally modulated to encode information onto a carrier signal.
“This functionality has never been demonstrated in a laser before,” said Piccardo. “We have shown that the laser can act as a so-called quadrature modulator, allowing two different pieces of information to be sent simultaneously through a single frequency channel and successively be retrieved at the other end of a communication link.”
“Currently, terahertz sources have serious limitations due to limited bandwidth,” said Capasso. “This discovery opens up an entirely new aspect of frequency combs and could lead, in the near future, to a terahertz source for wireless communications.”
Learn more: Laser frequency combs may be the future of Wi-Fi
The Latest on: Terahertz wireless communications
via Google News
The Latest on: Terahertz wireless communications
- Towards 6G-enabled Internet of Vehicles: Security and Privacyon January 15, 2022 at 7:04 pm
The conceptualisation of the sixth generation of mobile wireless networks (6G) has already started with some potential disruptive technologies resonating as enablers for driving the emergence of a ...
- Keysight to start 6G tests in California, Washingtonon January 12, 2022 at 12:29 pm
Keysight told the FCC it will design, develop, test and demonstrate 6G electronic test and measurement technologies at its indoor facilities. Keysight's tests will focus on spectrum bands between ...
- Address digital baseband to unlock THz communications for 6Gon January 12, 2022 at 8:11 am
To unlock the ultra-high data rates and high-frequency radio communications integral to future 6G technologies, we need ultra-fast encoding and decoding for the baseband chipset, also known as channel ...
- Chinese laboratory hails 6G breakthrough with record speed teston January 12, 2022 at 6:21 am
A Chinese laboratory has made a breakthrough in 6G-oriented terahertz 100/200 Gbits/sec real-time wireless communication with what it claims is the fastest speed ever recorded. Purple Mountain ...
- Chinese lab claims world record with 6G breakthrough, 10 to 20 times faster than 5Gon January 11, 2022 at 2:36 am
The recorded speed, which was about 10-20 times faster than those of most 5G networks, was a breakthrough for terahertz (THz) wireless communication, CGTN reported. According to the lab’s research ...
- Chinese lab achieves 100/200 Gbps in 6G Terahertz researchon January 10, 2022 at 2:51 am
China's Zijinshan Laboratory in Nanjing announced a major achievement in 6G-oriented terahertz wireless communication, with a transmission rate 10-20 times higher than 5G networks, according to a post ...
- China sets 6G speed world record, 10 to 20 times faster than 5Gon January 6, 2022 at 7:32 pm
With high-end 6G technologies, China has realized the world's fastest real-time transmission for terahertz wireless communication which is 10 to 20 times higher than 5G networks, the Purple Mountain ...
- Vaccination Trackeron January 5, 2022 at 11:38 pm
A high-tech laboratory in Nanjing, capital of East China's Jiangsu Province, has announced a major achievement related to 6G-oriented terahertz 100/200Gbps (gigabits per second) real-time wireless ...
via Bing News