New class of laser could reduce internet energy use
Researchers at Surrey have demonstrated the feasibility of a new type of semiconductor laser – used to transmit internet signals – which is more energy efficient and temperature stable than conventional crystal-based lasers.
The research, which was published in Scientific Reports in July, is the result of a €4 million EU-funded project led at Surrey by Professor Stephen Sweeney, Head of Surrey’s Department of Physics, involving academic and industrial partners from the UK, Germany, Ireland and Lithuania.
"This research has proved that there is a viable alternative to current indium phosphide-based lasers which could make these advanced energy efficient technologies feasible and widely accessible." - Professor Sweeney
With an exponential rise in internet data consumption over the past few years – a trend which will only increase with the emerging Internet of Things (whereby billions of devices will become connected) – the telecoms sector needs to reduce the level of energy used to provide connectivity. The semiconductor crystal-based lasers currently used for optical fibre communications are inefficient (losing around 80 per cent of their energy through heat) and can only operate in a temperature-controlled environment, requiring even higher energy use.
Surrey’s research shows that it is possible to develop lasers based on new semiconductor materials containing bismuth, which are more energy efficient than conventional lasers and far less sensitive to temperature. During the four year project, the research team conducted experimental research and computer-based modelling before fabricating and testing the prototype devices using facilities in the University’s Advanced Technology Institute (ATI).
In addition to their use in the telecommunications sector, the new lasers also have potential applications in sensing equipment such as breath sensors used in medical diagnosis.
Professor Sweeney said, “The internet is central to our lives today but already accounts for around four per cent of the total energy used worldwide. If we are to realise the full potential of future communications – including the 5G technologies we are developing here at Surrey – it is vital that we find a way of using less energy in order to reduce environmental impact and bring down costs while maintaining the connectivity that we have all grown to rely upon”.
“This research has proved that there is a viable alternative to current indium phosphide-based lasers which could make these advanced energy efficient technologies feasible and widely accessible.”
‘Optical gain in GaAsBi/GaAs quantum well diode lasers’ was published in Scientific Reports on 1 July 2016.
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