Energy efficient processes are increasingly key priorities for ICT companies with attention being paid to both ecological and economic drivers. Although in some cases the use of ICT can be beneficial to the environment (for example by reducing journeys and introducing more efficient business processes), countries are becoming increasingly aware of the very large growth in energy consumption of telecommunications companies. For instance in 2007 BT consumed 0.7% of the UK's total electricity usage. In particular, the predicted future growth in the number of connected devices, and the internet bandwidth of an order of magnitude or two is not practical if it leads to a corresponding growth in energy consumption. Regulations may therefore come soon, particularly if Governments mandate moves towards carbon neutrality. Therefore the applicants believe that this proposal is of great importance in seeking to establish the current limits on ICT performance due to known environmental concerns and then develop new ICT techniques to provide enhanced performance. In particular they believe that substantial advances can be achieved through the innovative use of renewable sources and the development of new architectures, protocols, and algorithms operating on hardware which will itself allows significant reductions in energy consumption. This will represent a significant departure from accepted practices where ICT services are provided to meet the growing demand, without any regard for the energy consequences of relative location of supply and demand. In this project therefore, we propose innovatively to consider optimised dynamic placement of ICT services, taking account of varying energy costs at producer and consumer. Energy consumption in networks today is typically highly confined in switching and routing centres. Therefore in the project we will consider block transmission of data between centres chosen for optimum renewable energy supply as power transmission losses will often make the shipping of power to cities (data centres/switching nodes in cities) unattractive. Variable renewable sources such as solar and wind pose fresh challenges in ICT installations and network design, and hence this project will also look at innovative methods of flexible power consumption of block data routers to address this effect. We tackle the challenge along three axes: (i) We seek to design a new generation of ICT infrastructure architectures by addressing the optimisation problem of placing compute and communication resources between the producer and consumer, with the (time-varying) constraint of minimising energy costs. Here the architectures will leverage the new hardware becoming available to allow low energy operation. (ii) We seek to design new protocols and algorithms to enable communications systems to adapt their speed and power consumption according to both the user demand and energy availability. (iii) We build on recent advances in hardware which allow the block routing of data at greatly reduced energy levels over electronic techniques and determine hardware configurations (using on chip monitoring for the first time) to support these dynamic energy and communications needs. Here new network components will be developed, leveraging for example recent significant advances made on developing lower power routing hardware with routing power levels of approximately 1 mW/Gb/s for ns block switching times. In order to ensure success, different companies will engage their expertise: BT, Ericsson, Telecom New Zealand, Cisco and BBC will play a key role in supporting the development of the network architectures, provide experimental support and traffic traces, and aid standards development. Solarflare, Broadcom, Cisco and the BBC will support our protocol and intelligent traffic solutions. Avago, Broadcom and Oclaro will play a key role in the hardware development.

Since the development of the first Kerr-lens mode-locked lasers in 1990, practical femtosecond lasers in a wide variety of configurations have delivered handsomely to a significant number of major scientific developments. It has to be recognised that the application space remains limited by the cost, complexity, skilled-user requirements and restricted flexibility of the current generation of ultrafast lasers. In this proposed joint project we seek to lead the way in the development of a new generation of ultrafast lasers. By adopting a modular approach for laser design we am aiming to demonstrate a platform from which lasers can be designed to address a wide range of user-specific requirements. By taking this approach, lasers for use in communications, for example, will have the necessary high repetition rates and low peak powers whereas for biophotonics high peak powers will be delivered to take full advantage of exploitable optical nonlinearities. We plan to work with vibronic crystals in both bulk and waveguide geometries and semiconductor quantum dot structures as the primary gain media. Although vibronic crystals have been deployed widely in ultrashort-pulse lasers the flexibility offered by conventional laser designs is very limited. To remedy this situation we intend to revolutionise cavity design to enable electrical control of the laser output parameters. For example, we wish to provide a means to users to change from an unmodelocked status to a femtosecond-pulse regime at the flick of switch. Also, by exploiting waveguiding in the vibronic crystals we are confident that we can introduce a new generation of highly compact lasers that will combine many of the advantages of a semiconductor laser with the most attractive features of crystal based devices. In some preliminary work in the Ultrafast Photonics Collaboration we have shown the potential of semiconductor quantum dot structures as broadband gain media that Can support the amplification and generation of femtosecond optical pulses. We now seek to build on those promising results and make the push towards truly flexible ultrafast lasers that will be amenable to external electronic control of the gain and loss components. Progress is expected to lead to a new generation of lasers that can give applications compatibility that far exceeds that available in traditional laser system designs. Within this strategy we plan to employ hybrid approaches where the benefits of semiconductor lasers will be combined with the energy storage capabilities of crystals to deliver compact and rugged sources having pulse characteristics that cover a range of durations, energies and profiles.A major part of this project effort will be devoted to the development of control functionality in ultrafast lasers. The intention is to use direct electrical control of intracavity components to deliver designer options for pulse shaping, modulated data streams, wavelength tuning and tailored dispersion. To ensure that this research is applicable we will evaluate the laser developments in the context of a set of identified demonstrators. These implementations will be used to show how design flexibility can deliver optimised lasers for biological, medical, communications and related applications.We have put together a research team having complementary of expertise and established track records of international excellence in photonics. This project as a whole will be managed from St Andrews University but all three research groups will undertake interactive research on all aspects of the laser development. We are confident that the work of this team will represent cutting-edge fundamental and translational research and it should represent a world leading strength for the UK in the development of new ultrafast lasers.

Since the development of the first Kerr-lens mode-locked lasers in 1990, practical femtosecond lasers in a wide variety of configurations have delivered handsomely to a significant number of major scientific developments. It has to be recognised that the application space remains limited by the cost, complexity, skilled-user requirements and restricted flexibility of the current generation of ultrafast lasers. In this proposed joint project we seek to lead the way in the development of a new generation of ultrafast lasers. By adopting a modular approach for laser design we are aiming to demonstrate a platform from which lasers can be designed to address a wide range of user-specific requirements. By taking this approach, lasers for use in communications, for example, will have the necessary high repetition rates and low peak powers whereas for biophotonics high peak powers will be delivered to take full advantage of exploitable optical nonlinearities. We plan to work with vibronic crystals in both bulk and waveguide geometries and semiconductor quantum dot structures as the primary gain media. Although vibronic crystals have been deployed widely in ultrashort-pulse lasers the flexibility offered by conventional laser designs is very limited. To remedy this situation we intend to revolutionise cavity design to enable electrical control of the laser output parameters. For example, we wish to provide a means to users to change from an unmodelocked status to a femtosecond-pulse regime at the flick of switch. Also, by exploiting waveguiding in vibronic crystals we are confident that we can introduce a new generation of highly compact lasers that will combine many of the advantages of a semiconductor laser with the most attractive features of crystal based devices. In some preliminary work in the Ultrafast Photonics Collaboration we have shown the potential of semiconductor quantum dot structures as broadband gain media that Can support the amplification and generation of femtosecond optical pulses. We now seek to build on those promising results and make the push towards truly flexible ultrafast lasers that will be amenable to external electronic control of the gain and loss components. Progress is expected to lead to a new generation of lasers that can give applications compatibility that far exceeds that available from traditional laser system designs. Within this strategy we plan to employ hybrid approaches where the benefits of semiconductor lasers will be combined with the energy storage capabilities of crystals to deliver compact and rugged sources having pulse characteristics that cover a range of durations, energies and profiles.A major part of this project effort will be devoted to the development of control functionality in ultrafast lasers. The intention is to use direct electrical control of intracavity components to deliver designer options for pulse shaping, modulated data streams, wavelength tuning and tailored dispersion. To ensure that this research is applicable we will evaluate the laser developments in the context of a set of identified demonstrators. These implementations will be used to show how design flexibility can deliver optimised lasers for biological, medical, communications and related applications.We have put together a research team having complementary of expertise and established track records of international excellence in photonics. This project as a whole will be managed from St Andrews University but all three research groups will undertake interactive research on all aspects of the laser development. We are confident that the work of this team will represent cutting-edge fundamental and translational research and it should represent a world leading strength for the UK in the development of new ultrafast lasers.

We are on the verge of a global revolution in lighting, as efficient and robust light emitting diode (LED) based 'solid state lighting' (SSL) progressively replaces traditional incandescent and even fluorescent lamps and finds its way into new areas including signage, illumination, signalling, consumer electronics, building infrastructure, displays, clothing, avionics, automotive, sub-marine applications, medical prosthetics and so on. This technology has tended to be viewed, so far, primarily as a way to improve energy- and spectral-efficiency, but what has been relatively little studied or appreciated is its profound implications for the future of communications. We envisage the tremendous prospect of an entirely new form of high bandwidth communications infrastructure to complement, enhance and in some cases supercede existing systems. This LED-based technology will utilise the visible spectrum, largely unused for communications at present and more than 10,000 broader than the entire microwave spectrum. This promises to help address the 'looming spectral crisis' in RF wireless communications and to permit deployment in situations where RF is either not applicable (e.g. in underwater applications) or undesirable (e.g. aircraft, ships, hospital surgeries), but the implications are more fundamental even than that. The key point, in our view, is that lighting, display, communications and sensing functions can be combined, leading to new concepts of 'data through illumination' and 'data through displays'. Imagine, for example, a 'smart room', where 'universal illuminators' provide high-bandwidth communications, sensors monitoring the environment and people within it, provide positioning information and display functions, and monitor the quality of the light. Imagine novel forms of personal communications system that combine display functions and video with multiple, high-bandwidth communications channels. These could be through mobile personal communicators (developments of mobile phones or personal digital assistants) or even wearable and mechanically flexible displays. Our ambitious programme seeks to explore this transformative view of communications in an imaginative and foresighted way. The vision is built on the unique capabilities of gallium nitride (GaN) optoelectronics to combine optical communications with lighting functions, and especially on the capability of the technology to implement new forms of spatial multiplexing, where individual elements in high-density arrays of LEDs provide independent communications channels, but can combine as displays. We envisage ultra-high data density - potentially Tb/s/mm2 - arrays of LEDs in compact and versatile forms, and will develop novel transceiver technology on this basis on both mechancially rigid and mechanically flexible substrates. We will explore the implications of this approach for multi-channel waveguide and free-space optical communications, establishing guidelines and fundamental assessments of performance which will be of long-term significance to this new form of communications.

This proposal seeks funding to create a Centre for Doctoral Training (CDT) in Integrated Photonic and Electronic Systems. Photonics plays an increasing role in systems, ranging from sensing, biophotonics and manufacturing, through communications from the chip-to-chip to transcontinental scale, to the plethora of new screen and projection display technologies that have been developed, bringing higher resolution, lower power operation and enabling new ways of human-machine interaction. These advances have set the scene for a major change in commercialisation activity where photonics and electronics will converge in a wide range of information, sensing, communications, manufacturing and personal healthcare systems. Currently, systems are realised by combining separately developed photonic components, such as lasers and photodetectors with electronic circuits. This approach is labour intensive and requires many electrical interconnects as well as optical alignment on the micron scale. Devices are optimised separately and then brought together to meet systems specifications. Such an approach, although it has delivered remarkable results, not least the communications systems upon which the internet depends, limits the benefits that could come from the full integration of photonics with electronics and systems. To achieve such integration requires researchers who have not only deep understanding of their specialist area, but also an excellent understanding across the fields of electronic and photonic hardware and software. This proposal therefore seeks to meet this important need, building upon the uniqueness and extent of the UCL and Cambridge research, where research activities are already focussing on the direct monolithic integration of lasers with silicon electronics, new types of displays based on polymer and holographic projection technology, the application of photonic communications to computing, personal information systems and indeed consumer products (via board-to-board, chip to chip and later on-chip interconnects), the increased use of photonics in industrial processing and manufacture, techniques for the low-cost roll-out of optical fibre to replace the copper network, the substitution of many conventional lighting products with photonic light sources and extensive application of photonics in medical diagnostics and personalised medicine. Many of these activities will increasingly rely on more advanced electronic systems integration, and so the proposed CDT includes experts in electronic circuits, computer systems and software. By drawing these complementary activities together, and building upon initial work towards this goal carried out within our previously funded CDT in Photonic Systems Development, it is proposed to develop an advanced training programme to equip the next generation of very high calibre doctoral students with the required technical expertise, commercial and business skills, and thus provide innovation opportunities for the integration of photonic and electronics in new systems in the coming years. It should be stressed that the CDT will provide a wide range of methods for learning for research students, well beyond that conventionally available, so that they can gain the required skills. In addition to conventional lectures and seminars, for example, there will be bespoke experimental coursework activities, reading clubs, roadmapping activities, secondments to companies and other research laboratories and business planning courses. The integration of photonic and electronic systems is likely to widen the range of systems into which these technologies are deployed in other key sectors of the economy, such as printing, consumer electronics, computing, defence, energy, engineering, security and medicine. As a result, a key feature of the CDT will be a developed awareness in its student cohorts of the breadth of opportunity available and a confidence that they can make impact therein.