
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
[google_news title=”” keyword=”terahertz wireless communications” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Terahertz wireless communications
- A deep dive into polyimides for high-frequency wireless telecommunicationson July 26, 2024 at 10:43 am
As 5G technologies continue to evolve, scientists and engineers are already exploring new ways to turn things up a notch for 6G. One of the biggest challenges to address in both 5G and 6G is the many ...
- Radio Propagation Measurements and Channel Modeling: Best Practices for Millimeter-Wave and Sub-Terahertz Frequencieson July 9, 2024 at 5:00 pm
Frequencies from 100 GHz to 3 THz are promising bands for the next generation of wireless communication systems because of the wide swaths of unused and unexplored spectrum. Terahertz wireless ...
- New technique offers unprecedented control over light at terahertz frequencieson July 8, 2024 at 6:22 am
This innovation paves the way for advancements in terahertz-frequency microscopes, communication systems, and more. Researchers have developed a novel method for generating structured terahertz ...
- New technique offers unprecedented control over light at terahertz frequencieson July 7, 2024 at 5:00 pm
It holds great promise for various applications, including security scanners, medical imaging, and ultrafast communication. However, generating and controlling terahertz light effectively has ...
- This bizarre vortex doesn't just look cool — it can be a key cog in making scalable high-speed 6G networks a realityon July 7, 2024 at 5:00 pm
The future of super-fast 6G communications could lie in the use of flexible plates with eye-catching spirals of carbon nanotubes tuned to broadcast terahertz (THz) signals. In a new study ...
- Your Next Tunable Terahertz Attenuator Might Be an Aerogelon June 23, 2024 at 5:00 pm
How aerogels perform in terahertz attention roles. Attenuators, especially adjustable ones, are a vital part of the communication signal-path hardware. Providing this function in the terahertz ...
- Microwave photonics shineson March 10, 2024 at 6:46 pm
Future networks will be expected to support wireless communications at data rates ... to generate high-quality and frequency-tunable terahertz waves by beating two optical wavelengths with a ...
- Team achieves world's fastest data transmission rate using photonicson February 2, 2024 at 2:45 am
This method allows for cramming large volumes of data into the sub-terahertz band while maintaining ... and receiver of a 300 GHz-band wireless communication system, they achieved a single-channel ...
- Terahertz technologies explainedon February 7, 2023 at 8:49 am
Communications: Terahertz technology is being researched for use in wireless communications. THz radiation has shorter wavelengths than microwaves and therefore has higher bandwidth capacity for data ...
via Bing News