New technology eliminates noise in long distance telecommunications

Researchers from the Optoelectronics Research Centre at the University of Southampton, UK, have developed a special type of filter that can be used in high bit-rate optical systems to remove noise introduced when signals are transmitted over long distances. Current telecommunications systems that transmit signals from one point to another suffer from noise that can reduce the quality of the signal. This new system has the potential to eliminate noise altogether and create much clearer signals, transforming next-generation telecommunications networks.

The ORC has an expertise in developing these filters, which are formed using superstructured fibre Bragg grating technology. Using this technology, the team has recently achieved precise processing of ultrashort optical pulses, and has developed the ability to manipulate and control accurately both their phase and amplitude characteristics.

This significant discovery helps overcome the current requirement to convert optical signals into the electrical domain for processing. The filter enables a much more effective way of transmitting and controlling signals because transmission speeds are not restricted to the slower speeds associated with electronic switches.

The application of these filters has been tested in high bit-rate systems, provided by the COM Centre in Copenhagen, unleashing the potential of ‘all optical networks’.

‘Superstructured fibre Bragg grating filters have several advantages over alternative solutions,’ explains Dr Periklis Petropoulos, a member of the research team at the ORC. ‘Our filters are more compact and we can produce them in large volumes without the need to use special phase masks, making them much cheaper. In addition, our filters are not polarisation sensitive which means that they are easier to apply to a real system.’

Dr Petropoulos continues: ‘We are fortunate enough to be able to work with the COM Centre in Copenhagen and pool resources to obtain these results. We provide the device and subsystem design and COM provide the 160Gbit/s testbed.’

The results of this joint experiment were reported in a paper which received the ‘Best Paper Award’ at one of the main conferences on optical communications, OECC/IOCC 2007 (Optoelectronics and Communications Conference/Integrated Optics and Optical Fiber Communication).

A second paper revealing further results from the joint experiments has been chosen as an invited paper at Europe’s largest optical communications event, ECOC, where it will be presented by Dr Francesca Parmigiani, another member of the ORC team. This major international conference will be held in Berlin (16 – 20 September).

Developments in fibre technology have revolutionised society and the ORC has been at the forefront of optical fibre communications since the very earliest days, providing several critical contributions over the years. This latest discovery will help contribute to the development of telecommunications systems and networks of the future by exploiting the features and properties of photonic technologies.

Ends

Notes for editors

1. The paper "160 Gb/s retiming using rectangular pulses generated using a superstructured fibre Bragg grating" L.K.Oxenlowe, F.Parmigiani, M.Galili, D.Zibar, A.T.Clausen, M.Ibsen, P.Petropoulos, D.J.Richardson, P.Jeppeson, was presented at OECC/IOOC 2007, Yokohama, 9-13 July 2007, paper 13B3-4.

The work reported in this paper was a joint experiment between the ORC and the COM Centre in Copenhagen (Denmark).

The invited paper which will presented at ECOC (Berlin 16-20 Sep 2007) is “All-optical 160 Gbit/s RZ data retiming system incorporating a pulse shaping fibre Bragg grating” F.Parmigiani, L.K.Oxenlowe, M.Galili, M.Ibsen, D.Zibar, P.Petropoulos, D.J.Richardson, A.T.Clausen, P.Jeppesen.

2. The work is funded by Cost Action 291 and the E-Photon/ONe+ network of excellence supported by the EU.

3. A transmission rate of 160Gbit/s implies that 160 billion data pulses are transmitted every second in the same optical fibre and over the same wavelength of light.

4. The Optoelectronics Research Centre at the University of Southampton is one of the largest university-based research groups entirely devoted to optoelectronics in the world, and has maintained a position at the forefront of photonics research for over four decades. Its long and well established track record in the fields of optical fibre, lasers, waveguides, devices and optoelectronic materials has fostered innovation, enterprise, cross-boundary and multi-disciplinary activities. It has built strong links with industry, research institutions and universities around the world, from informal collaborations to large-scale funding. Several spin out companies, including Southampton Photonics Inc, Stratophase Ltd, Mesophotonics Ltd and ChG Southampton Ltd, have commericalized the fruits of ORC research; while its extensive outreach programme has brought lasers and optical fibres into schools across the country.

Further information

Dr Periklis Petropoulos, Optoelectronics Research Centre, tel: +44 (0)23 8059 3141; email: pp@orc.soton.ac.uk

Marketing Officer, Optoelectronics Research Centre, tel: +44 (0)23 8059 3877; email: light@orc.soton.ac.uk