UCL claims breakthrough to bring FTTH to the masses

Researchers at the University College London have claimed the breakthrough of an optical access tech to expedite the arrival of FTTH in the UK.

UCL’s optical networks research group has worked on an alternative optical receiver which, in essence, enables operators to feed fibre networks directly to the consumer home. According to UCL, the group simplified the design of the optical receiver, improving sensitivity and network reach compared to existing technology. It says that the upgraded optical receiver will have the potential to lower the cost of installing and maintaining active components between the cabinet and the home.

Speaking on the announcement, the lead researcher for UCL’s electronic and electrical engineering group, Sezer Erkilinc, said the breakthrough could enable huge data rate speeds and support internet and data-consuming services of the future.

“We have designed a simplified optical receiver that could be mass-produced cheaply while maintaining the quality of the optical signal,” he said. “The average data transmission rates of copper cables connecting homes today are about 300 Mb/s and will soon become a major bottleneck in keeping up with data demands, which will likely reach about 5-10 Gb/s by 2025. Our technology can support speeds up to 10 Gb/s, making it truly future-proof.”

The proposition was put forward in the IEEE-backed Journal of Lightwave Technology, in the snappily titled paper “Polarization-Insensitive Single Balanced Photodiode Coherent Receiver for Long-Reach WDM-PONs”. Co-author of the paper Seb Savory, of the University of Cambridge, said it’s a case of simplifying the requirements of optical receivers.

“Our receiver is much simpler, containing just a quarter of the detectors used in a conventional coherent optical receiver,” he said. “We achieved this by applying a combination of two techniques. First a coding technique often used in wireless communications was used to enable the receiver to be insensitive to the polarisation of the incoming signals. Second we deliberately offset the receiver laser from the transmitter laser with the additional benefit that this allows the same single optical fibre to be used for both upstream and downstream data.

“One we’ve quantified the laser stability, we will be in a strong position to take the receiver design through field trials and into commercialisation. It is so exciting to engineer something that may one day be in everyone’s homes and make them a part of the digital revolution.”