Abstract
This presentation will discuss research carried out on the energy efficiency of optoelectronic components and systems at the Centre for Photonic Systems, University of Cambridge. This field of research has arisen because of the growth in energy consumption of Information Technology (IT). For example, it has been estimated that by 2020, carbon emission from data centres alone will exceed that of the airline industry, and indeed that in certain parts of the world, the IT industry already accounts for about 10% of global electricity consumption. Early work on this topic at Cambridge began in the late 1990s when it became clear that communication lasers would be required to operate in an uncooled environment for internet applications, so that the use of temperature controllers (consuming approximately ten times the power of the lasers themselves) could be avoided. In collaboration with Hewlett Packard, the group carried out a study of the gain properties of laser diodes at elevated temperatures, this resulting in the demonstration of the first uncooled 10 Gb/s laser diode.
Following a brief review of this work, the presentation will report on a range of techniques allowing yet higher bit rate performance with low energy consumption. For example, in recent years, aware that higher communication bandwidths will necessitate the use of multichannel techniques, work has focussed on the development of wavelength division multiplexed systems which despite operating potentially at 1 TB/s are able to operate uncooled. Over the past year this has been achieved and following this milestone, greater emphasis within our research is focussed on the use of optical routing to reduce energy consumption further.

Biography, Professor Ian White
Professor Ian White is currently Master of Jesus College, van Eck Professor of Engineering, Deputy Vice-Chancellor and Head of Photonics Research at the Department of Engineering, University of Cambridge. Ian is originally from Northern Ireland, coming to Jesus College in 1977 to read Engineering. He gained his BA and PhD degrees from the University of Cambridge in 1980 and 1984. He was then appointed a Research Fellow and Assistant Lecturer at the University of Cambridge before becoming Professor of Physics at the University of Bath in 1990. He moved in 1996 to the University of Bristol, before returning to the University of Cambridge in October 2001. At Cambridge he has also previously held the roles of Head of the School of Technology and Pro-Vice-Chancellor for Institutional Affairs.
Ian has contributed to a variety of research activities in photonics, ranging from short pulse laser diodes, optoelectronic components for signal processing and routing, high speed components for data communications, to techniques for transmitting digital and radio frequency signals over long distances of multimode optical fibre. He has published in excess of 900 journal and conference papers, and is co-founder of Zinwave Ltd and PervasID Ltd.
Ian is a Fellow of the Royal Academy of Engineering, the Institution of Electrical Engineers and the Institute of Electrical and Electronics Engineers. He is heavily involved in policy development and administration of research and sits on a number of International Conference Committees. He was a Member of the Board of Governors of the IEEE Photonics Society (2008-2012).