DESLEY BLANCH : Fibre optic cables just became more energy-efficient to the point where all of the world’s internet traffic could travel on a single fibre.
The Australian scientists say the breakthrough uses commercial components manufactured in Australia to optimise the efficiency of the existing optical fibre networks that connect towns and cities.
It could dramatically boost the overall performance of networks like Australia’s National Broadband Network while reducing costs.
Monash University engineers Professor Arthur Lowery and Dr Liang Du collaborated with colleagues at the University of Sydney’s Centre of Excellence for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS).
Their technique was presented at the world’s largest optical communications conference in California late last month.
Professor Arthur Lowery is leader of the Optical Communications Laboratory at Melbourne’s Monash University who explains how they’ve expanded their fibre carrying capacity by using a continuous rainbow of colours.
PROFESSOR ARTHUR LOWERY : Over the last seven years we’ve been working on ways of packing more data down an optical fibre. Rather than having discrete colours, so red, blue, for example, we’re actually creating a rainbow of colours that is continuous. We used to do this with electronic computation, very fast and power hungry electronic computation. Now we’re doing it with all optical techniques.
DESLEY BLANCH : So after reprogramming the network component, what speeds did you reach for transmission using fibre and over what sort of distances, because they were quite long distances, weren’t they?
PROFESSOR ARTHUR LOWERY : Yes, we have been transmitting at 10 terabits per second, that’s ten-thousand billion bits per second and over a distance of 856 kilometres, so that’s the amount of fibre we have in the lab.
DESLEY BLANCH : And then how does this new speed compare with current speeds and methods?
PROFESSOR ARTHUR LOWERY : There have been demonstrations of optical fibres at 100 terabits per second. The advantage we have is that we’re generating these signals using optical techniques and we could potentially reach those capacities given more equipment, but what we’ve said is, that we can pack a lot of data into a small amount of spectrum--a small colour range--and, of course we can play this trick over and over again and pack other chunks of ten terabits per second in other bits of the fibre spectrum, so we could reach higher speeds even though we didn’t report them at this particular conference.
DESLEY BLANCH : So this is so much faster than what we experience in today’s conditions?
PROFESSOR ARTHUR LOWERY : Yes. The end-user experience of course, comes through ADSL or cable and so, most people have never experienced much beyond 100 megabits per second.
But the links we’re talking about are links between cities and continents and, because 60 per cent of the internet really comes from abroad when people do searches, it’s really important to have these transnational links in place, because if everybody wants 100 megabits per second and there’s ten million people, then that starts to use up the whole capacity of a fibre if you don’t have our techniques.
DESLEY BLANCH : Now, the Sydney researchers at CUDOS reprogrammed the wave length selective switch. Professor Ben Eggleton and Jochen Schroeder were part of that team. So what did you do, how did you go about that, Jochen?
DR JOCHEN SCHROEDER : What we did in over the last two or three years, is that we found a new way of programming these devices using computer-generated holography to really take on the role of the electronic processing in the networks that Arthur talked about earlier and do this all optically and so by reprogramming this saves significant energy because we don’t have to use the power hungry electronics.
DESLEY BLANCH : Now, the switch allows you to fill gaps in the data traffic. So can you give us a quick lesson in how data traffic flows around between our cities and countries?
DR JOCHEN SCHROEDER : Traffic is transmitted through optical fibres between our big cities and these devices that we reprogrammed, these wave length selective switches are actually routers. They’re essentially like traffic intersections that can direct traffic from one city to the next and if a data packet wants to, sort of, get off at this highway at this city then it’s directed to an interchange and then it is further directed to the home.
DESLEY BLANCH : So Ben Eggleton, by using the switch, the signals could squeeze into gaps in the data traffic and significantly you could fit new traffic squeezed into this fibre as well, couldn’t you?
PROFESSOR BEN EGGLETON : Yeah, well that’s right. And this is really exciting because we’re imagining that the capacities in these networks, is growing exponentially. Over the next ten years, we’re looking at 1,000 times more bandwidth.
The National Broadband Network will completely change the nature of the internet as far as we have so far seen in Australia. So this collaboration, which was part of the CUDOS ARC Centre of Excellence working with Finisar Corporation in Sydney has developed a really exciting, enabling technology that will allow more bandwidth, more data to be squeezed through these fibres and that, at the end of the day will allow users to keep up with the increasing traffic demands that we’re all expecting and wanting in the future.
DESLEY BLANCH : And apparently, instead of laying hundreds of new parallel optical fibres to boost network capacity you can actually do it on your one single fibre?
PROFESSOR BEN EGGLETON : Yeah, that’s right. And I paraphrase one of our really exciting goals at CUDOS. We talk about photonics enabling the new information age faster, smaller, smarter and greener. So our vision is to deliver more bandwidth--that’s faster; to deliver that bandwidth more intelligently--smarter and at the same time to do it greener. Of course, that means consuming less energy.
So as Professor Lowery has mentioned, the all optical approach that we’re introducing here, it avoids the requirement of high speed electronics so we’re reducing the power consumption, the electricity demands by all of the magnitudes, and that’s going to become critically important as these networks are growing exponentially as I mentioned.
DESLEY BLANCH : Less than twelve months ago, Dr Liang Du received an award for his ideas of faster data. Liang how did your ideas for faster data fit into this project or didn’t they? Did they come together in any way?
DR LIANG DU : At Monash University, we’ve had a common theme of doing research in optical OFDM (Orthogonal Frequency Division Multiplexing) because OFDM is a very efficient way of packing data in a limited spectrum.
But the key breakthrough in this particular piece of work is that we were able to use optical techniques to multiplex the channels.
PROFESSOR BEN EGGLETON : This is a real breakthrough because it really represents a new paradigm for transmitting data, lower energy. It generated a real buzz at the conference. We’ve been very busy the last week talking to the media in Australia, obviously very relevant in the Australian context with the National Broadband Network. So we’re really thrilled.
It’s the beginning of a new phase in our research. It’s established a new principle. I think it’s a very promising approach. Obviously there are commercialisation opportunities. We’re looking to our industry partners in Australia to take advantage of this opportunity, maximise the opportunity to create some new technology that we can manufacture in Australia.
DESLEY BLANCH : So given that, if you’re using equipment that’s already on the market here, can you give us a time when this technology could be fed through to us as the consumers?
PROFESSOR BEN EGGLETON : Well that’s the really exciting point. It is based on some off-the-shelf components. Essentially the intellectual property really is in the idea that we’re combining building blocks to create something completely new.
In principle, this could be taken to market pretty swiftly through our industry partner, Finisar, they’re based in Waterloo, Sydney. They’ve got a real track record in the area. It could be deployed I could imagine in the next twelve-eighteen months if we can really move quickly in this area.
DESLEY BLANCH : Ben Eggleton; he is Professor of Physics at the University of Sydney and is the founding Director of CUDOS (the Centre of Excellence for Ultrahigh Bandwidth Devices for Optical Systems).
We also heard from Dr Jochen Schroeder another of the CUDOS researchers; and from Professor Arthur Lowery and Dr Liang Due from Melbourne’s Monash University’s Department of Electrical Engineering and Computer Systems Engineering who all together have optimised the carrying capacity of fibre optical cable.
It’s hard to imagine these increased fibre efficiencies of 10 terabits per second and beyond. That’s ten-thousand-billion bits per second; while most of us haven’t experienced much beyond the 100-megabits per second.