Photonics – defined by some as anything to do with the creation, capture and modification of light – is big business, even though it may not appear so on first sight.

The largest of the six key enabling technologies identified by the European Commission, photonics contributes more than €65billion a year to the European economy, whilst employing 377,000 people directly in 5000 companies. In the UK, there are more than 1000 photonics related companies, employing 70,000 people, with the technology adding more than £10bn a year to the economy. Global demand for photonics is thought to exceed €365bn a year.

Despite the industry’s size, the technology is seeing more investment in R&D. While the recently announced Future Photonics Hub (see p16 in this issue) is one example, another is the UCL-Cambridge Centre for Doctoral Training in Integrated Photonic and Electronic Systems (IPES)

IPES’ director Professor Alwyn Seeds told the meeting the Centre is looking to work on real problems and to encourage its students to interact with industry partners and other researchers. It receives more than 150 applications per year and makes about 25 offers. “We recruit from a range of technology backgrounds and this works well in terms of inter disciplinary research,” he said.

Andrew Lord, director of optical research with BT, gave the keynote address at a recent seminar outlining IPES’ work, describing how photonics is set to enable the next era of communications.

He told the audience that BT’s optical research was focused in a number of areas, including: core transport; backhaul; optical access; quantum communications; elastic optical networks; and software defined networks.

“This work is being driven by huge growth in network demand – it’s grown by a factor of 100 in the last 10 years,” he noted, “with core broadband traffic growing at 65% a year.”

One of the possible solutions is ultra high bit rate transmission and BT is making progress in this area; Lord said demonstrations had shown ‘real time’ data rates of 4Tbit/s could be maintained over several weeks, with so called ‘superchannels’ carried over long distances.

“While we’re trying to make sure the technology is robust,” he continued, “we also need flexibility. There’s always been flexibility at the IP level, but you can’t do that optically unless you try optical packet switching, which hasn’t taken off.”

BT is looking to develop flexibility in optical communications “For example,” he said, “dynamically adjustable transponders could double the available bandwidth, whilst ‘playing’ with the spectrum to get rid of gaps could potentially add another 30%. Combine these two and we’ll get a lot more capacity,” he added, noting that prototypes are starting to be tested.

He compared the situation with the radio industry making the best use of the spectrum. “Optical hasn’t had to worry about this until recently. Before, we just put in another fibre; now, we have to control communications in real time and we should be able to get this through software defined networks.”

And this is the ‘elasticity’ concept which Lord trailed. “We’re looking at how software comes together with the data plane, but this needs abstraction – I don’t want to understand everything about how a multi Terabit router works, I just need to control the basics and this could be part of a network.”

Meanwhile, BT continues to develop quantum cryptography. Recently, it joined with Toshiba Research Europe and ADVA Optical Networking to demonstrate quantum cryptography in use on a system with a bandwidth of 200Gbit/s over a single 100km fibre. “Quantum technology makes it very much more difficult to access data,” Lord concluded.