Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Communication technologies including smartphones and laptops could now be 1,000 times faster

The Pitt team has generated a frequency comb with more than a 100 terahertz bandwidth as a means to process communications data at a remarkably rapid speed

Many of the communication tools of today rely on the function of light or, more specifically, on applying information to a light wave. Up until now, studies on electronic and optical devices with materials that are the foundations of modern electronics—such as radio, TV, and computers—have generally relied on nonlinear optical effects, producing devices whose bandwidth has been limited to the gigahertz (GHz) frequency region. (Hertz stands for cycles per second of a periodic phenomenon, in this case 1billion cycles).

Thanks to research performed at the University of Pittsburgh, a physical basis for terahertz bandwidth (THz, or 1 trillion cycles per second)—the portion of the electromagnetic spectrum between infrared and microwave light—has now been demonstrated.

In a paper published March 4 in Nature Photonics, Hrvoje Petek, a professor of physics and chemistry in Pitt's Kenneth P. Dietrich School of Arts and Sciences, and his colleague Muneaki Hase, a professor of applied physics at the University of Tsukuba in Japan and a visiting scientist in Petek's lab, detail their success in generating a frequency comb—dividing a single color of light into a series of evenly spaced spectral lines for a variety of uses—that spans a more than 100 terahertz bandwidth by exciting a coherent collective of atomic motions in a semiconductor silicon crystal.

"The ability to modulate light with such a bandwidth could increase the amount of information carried by more than 1,000 times when compared to the volume carried with today's technologies," says Petek. "Needless to say, this has been a long-awaited discovery in the field."

To investigate the optical properties of a silicon crystal, Petek and his team investigated the change in reflectivity after excitation with an intense laser pulse. Following the excitation, the team observed that the amount of reflected light oscillates at 15.6 THz, the highest mechanical frequency of atoms within a silicon lattice. This oscillation caused additional change in the absorption and reflection of light, multiplying the fundamental oscillation frequency by up to seven times to generate the comb of frequencies extending beyond 100 THz. Petek and his team were able to observe the production of such a comb of frequencies from a crystalline solid for the first time.

"Although we expected to see the oscillation at 15.6 THz, we did not realize that its excitation could change the properties of silicon in such dramatic fashion," says Petek. "The discovery was both the result of developing unique instrumentation and incisive analysis by the team members."

Petek notes the team's achievements are the result of developing experimental and theoretical tools to better understand how electrons and atoms interact in solids under intense optical excitation and of the invested interest by Pitt's Dietrich School in advanced instrumentation and laboratory infrastructure.

The team is currently investigating the coherent oscillation of electrons, which could further extend the ability of harnessing light-matter interactions from the terahertz- to the petahertz-frequency range. Petahertz is a unit of measure for very fast frequencies (1 quadrillion hertz).

This research was funded by a grant from the National Science Foundation.

For more information on Petek's research, visit

B. Rose Huber | EurekAlert!
Further information:

More articles from Communications Media:

nachricht High Number of Science Enthusiasts in Switzerland
05.02.2018 | Universität Zürich

nachricht Between filter bubbles, uneven visibility and transnationality
06.12.2017 | Schweizerischer Nationalfonds SNF

All articles from Communications Media >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>