This proposal is for a studentship to develop key systems for the Square Kilometre Array (SKA), to be held jointly by the University of Oxford Dept of Physics, which is one of the leading contributors to the SKA design and specifications, and Selex Galileo, a leading European electronics company. The SKA is a project to build by far the largest radio telescope ever constructed, which will have a transformative effect on many areas of astrophysics and cosmology. The key science goals of the SKA include mapping the development of the structure of the universe by measuring the positions in time and space of a billion galaxies; testing fundamental theories of physics by precision measurements of the most extreme objects in the universe; and studying the formation of earth-like planets. In its final form, it will consist of an array of around 2000 15-m dish antennas, plus around 500 large (~200-m diameter) phased array antennas covering two different frequency bands (totalling over ten square kilomtres of physical collecting area), plus a large central data processing facility, costing a total of around E1.5 billion. The antenna arrays will be concentrated in a remote desert site, with some elements spread over continental distances. The aperture arrays will be the largest digital signal processing networks ever built, with a total input data rate of several petabits per second (greater than the entire current internet) and processing power of many peta-operations per second (comparable to all the personal computers in the UK combined). The period covered by this proposed studentship coincides with the pre-construction phase of the SKA, during which the current plans and outline designs will be converted into functional prototype sub-systems which are capable of being manufactured and installed on an industrial scale. This is therefore the ideal time to have a joint academic-industrial studentship working on a critical aspect of the SKA Phase 1 system design, the low-band aperture array. By using a phased array instead of a large dish antenna, it is possible to image a large number of independent fields of view simultaneously, vastly increasing the survey speed. Once digitized, the signals from each antenna element are broken in to narrow frequency channels, then combined heirarchically into phased beams consisting of weighted sums of all the ~10,000 antenna elements in an array station. Complex gain factors applied to each input element both calibrate out amplitude and phase imbalances in the elements, and generate well-defined beams pointing to different parts of the sky. The project student will study the detailed implementation of the RF analogue electronics, digitization, and initial signal processing of the data streams. The performance requirements for the SKA, in terms of bandwidth, data throughput and volume of output data are far greater than any currently implemented system, and will require innovative design solutions, and a close interaction between science requirements and engineering implementations. Of particular importance is that the designs must be optimized for low manufacturing cost, ease of initial testing, low power consumption, and long service life with little or no maintenance. These are areas where Selex Galileo has vast experience and will bring a major input to the system design. The precise areas of study for the student will be fixed during the initial phase of the project rather than now; the student will not start until October 2011, and the overall system design will have moved on by then, and the scope of work available is also much greater than any one student could cover in a PhD. The supervisors will agree a programme of work which makes best use of the interests and skills of the student and the capabilities of the industrial partner, with the aim of maximising the impact of the project on the SKA design and hence the UK industrial involvement in the SKA construction phase.

Vision is arguably the most important of our senses and our most direct channel of interaction with the surrounding world. It is no surprise therefore that so much of the technology that affects our everyday lives relies on light in one form or the other. The continuous strive to improve our light sources, ranging from lasers for research purposed to ambient lighting technologies is paralleled by a continuous increase in efforts to improve our imaging capabilities, ranging from artificial vision implants to hyperspectral imaging. An exciting and emerging imaging technology relies on the ability to detect remarkably low light signals, i.e. even single photons. This same technology, based for example of Single-Photon-Avalanche-Detectors (SPADs) comes hand in hand with another rather unexpected and also remarkable feature: incredibly high temporal resolution and the ability to distinguish events that are separated in time by picoseconds or less. This temporal resolution is obtained by operating the SPAD in so-called Time-Correlated-Single-Photon-Counting (TCSPC) mode, where the single photons are detected in coincidence with an external trigger and then electronically stored with a precise time-tag that, after accumulating over many events, allows to precisely identify the photon arrival time. These technologies are now relatively well established and are routinely employed in research activities, mainly associated to quantum optics measurements and time of flight measurements. However, these detectors are all single pixel detectors and thus do not allow to directly reconstruct an image in much the same way that a digital camera with a single pixel will not create an image. Workaround solutions have been adopted; for example a laser may be scanned across an object and the single pixel records intensity levels for each position of the laser beam. However, our obsession with the pixel-count in our latest digital camera clearly explains the paradigm shift in going from a single pixel detector to a multi-pixel detector and eventually to high resolution imaging. ULTRA-IMAGE aims at demonstrating a series of applications of very novel SPAD technology: for the first time these detectors are available in imaging arrays. This is an emerging technology that will represent the next revolution in imaging and we will have first hand access to each technological breakthrough in SPAD array design, as they occur over the next few years. We are currently employing 32x32 SPAD arrays and will be using the first ever (at the time of writing) 320x240 pixel array, which is able to deliver the first high quality spatially resolved images. The remarkable aspect of these detectors is that they still retain their picosecond temporal resolution therefore enabling a series of game-changing and remarkable technological applications that are not even conceivable with traditional cameras. As examples of the potential of this new imaging technology, we will utilise our SPAD cameras to visualise the propagation of light and perform time-of-flight detection of remote objects in harsh environments (the FEMTO-camera), to enable of the real-time tracking of objects hidden from view (the CORNER-camera), and to perform the first quantum measurements using low-rep rate, high-power lasers (the QUANTUM-camera). The solutions we will develop are enabled by four key features: first, the single-photon sensitivity of silicon detectors; second, the spatial resolution provided by the arrayed nature of the detectors; third, the precise picosecond and femtosecond timing resolution; and fourth, the ultra low-noise performance of gated detection.

A Centre for Innovative Manufacture in Laser-based Production Processes is proposed. This Centre will exploit the unique capabilities of laser light to develop new laser-based manufacturing processes, at both micro and macro levels, supported by new laser source, process monitoring and system technologies. The past 25 years has seen industrial lasers replace many 'conventional' tools in diverse areas of manufacture, enabling increased productivity, functionality and quality, where for example laser processing (cut/join/drill/mark) has revolutionised automotive, aerospace and electronics production. However the penetration of laser technology into some areas such as welding and machining has been less than might have been anticipated. But recently there has been a significant 'step change-opportunity' to take laser-based processing to a new level of industrial impact, brought about by major advances in laser technology in two key areas: (i) A new generation of ultra-high quality and reliability lasers based around solid state technology (laser diode and optical fibre) has evolved from developments in the telecoms sector. These lasers are leading to systems with very high levels of spatial and temporal controllability. This control, combined with advanced in-process measurement techniques, is revolutionising the science and understanding of laser material interactions. The result of this is that major improvements are being made in existing laser based processes and that new revolutionary processes are becoming viable, e.g. joining of dissimilar materials. (ii) A new generation of high average power laser technologies is becoming available, offering controllable trains of ultrashort (picosecond and femtosecond) pulses, with wavelengths selectable across the optical spectrum, from the infrared through to the ultra-violet. Such technology opens the door to a whole range of new laser-based production processes, where thermal effects no longer dominate, and which may replace less efficient 'conventional' processes in some current major production applications. These new developments are being rapidly exploited in other high-value manufacturing based economies such as Germany and the US. We argue that for the UK industry to take maximum advantage of these major advances in both laser material processing and machine technology there is an urgent requirement for an EPSRC Centre for Innovative Manufacturing in Laser-based Production Processes. This will be achieved by bringing together a multi-disciplinary team of leading UK researchers and key industry partners with the goal of exploiting 'tailored laser light'. Together with our industrial partners, we have identified 2 key research themes. Theme A focuses on Laser Precision Structuring, i.e. micro-machining processes, whilst Theme B is focused on joining and additive processes. Spanning these themes are the laser based manufacturing research challenges which fall into categories of Laser Based Production Process Research and Laser Based Machine Technologies, underpinned by monitoring and control together with material science. Research will extend from the basic science of material behaviour modelling and laser-material interaction processes to manufacturing feasibility studies with industry. The Centre will also assume an important national role. The Centre Outreach programme will aim to catalyse and drive the growth of a more effective and coherent UK LIM community as a strong industry/academia partnership able to represent itself effectively to influence UK/EU policy and investment strategy, to promote research excellence, and growth in industrial take-up of laser-based technology, expand UK national knowledge transfer and marketing events and improve the coordination and quality of education/training provision.

Graphene is a single layer of graphite just one atom thick. As a material it is completely new - not only the thinnest ever but also the strongest. It is almost completely transparent, yet as a conductor of electricity it performs as well or even better than copper. Since the 2010 Nobel Prize for Physics was awarded to UK researchers in this field, fundamental graphene research has attracted much investment by industry and governments around the world, and has created unprecedented excitement. There have been numerous proof-of concept demonstrations for a wide range of applications for graphene. Many applications require high quality material, however, most high quality graphene to date is made by exfoliation with scotch tape from graphite flakes. This is not a manufacturable route as graphene produced this way is prohibitively expensive, equivalent to £10bn per 12" wafer. For high quality graphene to become commercially viable, its price needs to be reduced to £30-100 per wafer, a factor of 100 million. Hence graphene production and process technology is the key bottleneck to be overcome in order to unlock its huge application potential. Overcoming this bottleneck lies at the heart of this proposal. Our proposal aims to develop the potential of graphene into a robust and disruptive technology. We will use a growth method called chemical vapour deposition (CVD) as the key enabler, and address the key questions of industrial materials development. CVD was the growth method that opened up diamond, carbon nanotubes and GaN to industrial scale production. Here it will be developed for graphene as CVD has the potential to give graphene over large areas at low cost and at a quality that equals that of the best exfoliated flakes. CVD is also a quite versatile process that enables novel strategies to integrate graphene with other materials into device architectures. In collaboration with leading industrial partners Aixtron UK, Philips, Intel, Thales and Selex Galileo, we will develop novel integration routes for a diverse set of near-term as well as future applications, for which graphene can outperform current materials and allows the use of previously impossible device form factors and functionality. We will integrate graphene for instance as a transparent conductor into organic light emitting diodes that offer new, efficient and environmentally friendly solutions for general lighting, including a flexible form factor that could revolutionize traditional lighting designs. We will also integrate graphene into liquid crystal devices that offer ultra high resolution and novel optical storage systems. Unlike currently used materials, graphene is also transparent in the infrared range, which is of great interest for many sensing applications in avionics, military imaging and fire safety which we will explore. Furthermore, we propose to develop a carbon based interconnect technology to overcome the limitations Cu poses for next generation microelectronics. This is a key milestone in the semiconductor industry roadmap. As a potential disruptive future technology, we propose to integrate graphene into so called lab-on-a-chip devices tailored to rapid single-molecule biosensing. These are predicted to revolutionize clinical analysis in particular regarding DNA and protein structure determination.

AlGaN/GaN high electron mobility transistors (HEMT) are a key enabling technology for future high efficiency military and civilian microwave systems. The aim of this proposal is to provide transformative insight into the underlying physical processes that cause degradation in GaN RF power amplifiers (PA). This is of strategic importance for the UK given its strong RF electronics base, due to the fact that GaN RF power electronics delivers a disruptive step change in systems capability through power densities as high as 40W/mm and frequencies exceeding 300GHz. The UK has internationally leading academic research groups in this field, including Bristol and Cardiff. The key issue addressed in this proposal is that device degradation under RF stress is distinctly different than under DC stress, often resulting in a large increase in source resistance, something that never occurs under DC stress and is not explicable by conventional models. This observation implies that a device in RF operation applies voltage/current stresses, which are inaccessible under static conditions, making it imperative to understand the interaction between the RF operating mode and the degradation mechanism. Bristol has provided seminal contributions to the international effort to understand DC GaN transistor degradation, where an understanding is slowly emerging that includes oxygen related reactions and diffusion processes, and dislocation linked breakdown in GaN transistors. This includes electroluminescence imaging for detection of leakage pathways, dynamic transconductance and transient analysis to detect trapping states, and the simulation of the effect of pulsed operation on bulk and surface traps. Over the last 15 years, Cardiff has established a world leading capability in RF PA design and measurement. In particular waveform engineering systems enable RF current/voltage waveforms to not only be measured directly but also to be manipulated almost at will. This manipulation of the waveform has allowed Cardiff to make seminal contributions to the understanding of high efficiency RF PA operation. In this project, the unique capability to 'tune' RF operation into extremely well defined states to enable 'controlled' RF stressing will be used to gain the step change understanding of RF device degradation. Reverse engineering of failed devices, electrical and electro-optical measurement before/after and during the RF stress, combined with physical device simulation, will be used to determine the RF specific degradation mechanisms. This capability to predict, engineer and measure the RF waveforms is key to achieving an understanding of the RF stresses that devices undergo during PA operation, and then to determine and specify the safe-operating-area for HEMTs. This project utilises a partnership with state-of-the-art foundries in Germany and the USA, allowing the project to use production quality devices, essential for the relevance of the work. The project will be guided in terms of its relevance through guidance and interaction with Selex for systems level issues and IQE for the materials. The key synergy of Bristol and Cardiff will address a vitally important issue for the uptake of this disruptive technology, the identification of the RF degradation mechanisms. This will enable the impact of different modes of RF operation to be predicted, and a novel robust RF reliability test methodology to be developed, thus delivering large UK benefit and international impact.