With video content consuming ever more bandwidth, the need for faster data transmission rates has never been greater. Now a team of scientists at Germany's Karlsruhe Institute of Technology (KIT) are claiming a world record in data transmission with the successful encoding of data at a rate of 26 terabits per second on a single laser beam and transmitting it over a distance of 50 km (31 miles). The scientists claim this is the largest data volume ever transported on a laser beam and enables the transmission of 700 DVD's worth of content in just one second.

With no electronic processing methods available for a data rate of 26 terabits per second, the team developed a new opto-electric data decoding process. This process relies on purely optical calculations to break down the initial high data rate into smaller bit rates that can then be processed electrically. The record-breaking data encoding also employed the orthogonal frequency division multiplexing (OFDM) scheme based on Fast Fourier Transformation (FFT) mathematical routines that is commonly used in mobile communications networks including digital TV and audio broadcasts.

Because energy is required for the laser and a few process steps only, the team says the new method is not only extremely fast, but also very energy efficient.

"Our result shows that physical limits are not yet exceeded even at extremely high data rates," says Professor Jürg Leuthold, who led the KIT experiment. "A few years ago, data rates of 26 terabits per second were deemed utopian even for systems with many lasers and there would not have been any applications. With 26 terabits per second, it would have been possible to transmit up to 400 million telephone calls at the same time. Nobody needed this at that time. Today, the situation is different."

The latest breakthrough follows on from the previous high-speed data transmission record set by the KIT scientists in 2010, when they successfully exceeded the data rate of 10 terabits (or 10,000 billion bits) per second.

The KIT experiment involved companies and scientists from all over Europe, including members of the staff of Agilent and Micram Deutschland, Time-Bandwidth Switzerland, Finisar Israel, and the University of Southampton in Great Britain. The experiment is detailed in the journal Nature Photonics.