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.

The aim of this proposal is to demonstrate for the first time a semiconductor laser emitting transform-limited optical pulses of less than 200 fs duration in a diffraction-limited beam. This achievement will open the way for the development of truly compact ultrafast optical systems. Our device is a surface-emitting laser, optically pumped using the cheap and rugged technology developed for diode-pumped solid state lasers, with perfect beam quality enforced by an extended cavity. It emits a periodic train of ultrashort pulses at a repetition rate of a few GHz using the optical Stark effect passive mode-locking technique introduced by the Southampton group. Recent proof-of-principle experiments have shown that these lasers can generate stable 260-fs pulse trains. We have shown, moreover, by modelling and by experiment, that the optical Stark mechanism can shorten pulses down to durations around 70 fs, comparable with the quantum well carrier-carrier scattering time. Our proposal is to build on these world-leading results with a systematic exploration of the physics of lasers operating in this regime. The key is to grow quantum well gain and saturable absorber mirror structures in which dispersion, filtering and the placing of the quantum wells under the laser mode are controlled to tight tolerances. We shall achieve this using molecular beam epitaxy to realise structure designs that are developed with the aid of rigorous numerical modelling of the optical Stark pulse-forming mechanism. We shall also use femtosecond pump and probe spectroscopy to determine the dynamical behaviour of our structures in this regime directly. For these pioneering studies, the compressively-strained InGaAs/GaAs quantum well system operating around 1 micron is most suitable; and this is where we shall work; however, the devices that we develop can in principle in future be realised in other material systems in different wavelength regions. We shall also make a first study of incorporating quantum dot gain and absorber material into optical Stark mode-locked lasers, aiming to exploit the intrinsically fast carrier dynamics of these structures. In summary, this proposal aims to shrink femtosecond technology from shoebox-size to credit-card size, and in the process explore a regime of ultrafast semiconductor dynamics that has never before now been exploited to produce light pulses.

Lasers are rapidly becoming more useful - they are widely available at shorter wavelengths, emitting shorter pulses and at higher energies and powers than ever before. These characteristics make them especially useful for several industrial applications such as velocimetry, micro-machining and welding, where the beam characteristics delivered to the workpiece are critical in determining the success and efficiency of the process. Unfortunately, the very characteristics that make these laser pulses so useful - their short pulse lengths, low wavelengths and higher energy and power - make them absolutely impossible to deliver using conventional fibre optics. This means that those wishing to exploit the new laser systems would currently have to do so using bulk optics - typically, several mirrors mounted on articulated arms to deliver the pulses to the workpiece.We propose to use an alternative optical fibre technology to solve this problem. Hollow-core fibres which guide light using a photonic bandgap cladding have roughly 1000 times less nonlinear response than conventional fibres, and have far higher damage thresholds as well. In previous work, we concentrated on longer nanosecond pulsed lasers, and demonstrated that we could use these fibres to deliver light capable of machining metals. However, it is with the picoscond and sub-picosecond pulse laser systems now becoming more widespread that the hollow-core fibres really come into their own. For these shorter pulses, transmission through conventional fibres is limited not only by damage, but first by pulse dispersion and optical nonlinear response. These problems can only be surmounted using hollow-core fibre - no competing technology has come even close.Our work programme has several strands, with the common objective being to devise systems capable of delivering picosecond-scale pulses through lengths of a few metres of fibre, at useful energies and powers. To do this, we need to be able to efficiently couple light into the fibres and transmit them, single-mode, over a few metres of fibre with low attenuation. We plan to focus our attention on doing this in the wavelength bands around 1060nm and 530mn, and to investigate the possibility of extending the work to shorter wavelengths. We will work closely with several collaborators from the industrial/commercial sector, ranging from a UK-based supplier of relevant laser systems through to a company developing machining systems and indiustries which actually use such systems. In this way, we plan to provide UK-based industry with a competitive edge on teh global stage, by providing them with access to an academic area where the UK is an acknowledged world leader.

Our vision is to develop the disruptive component technologies and network concepts that will enhance our communications infrastructure 1000-fold to meet our 20-year needs, avert network grid-lock and reduce energy consumption.With continued steep growth in transmitted data volumes on all media, there is a widely-recognized and urgent need for more sophisticated photonics technologies in both the core and access networks to forestall a 'capacity crunch' in the medium term. Our Programme involves two world-class groups ideally positioned to satisfy this need and reinforce the traditional leadership of the UK in this area. All-optical technologies can also save considerably on the rapidly-rising energy consumption of communications systems (several % of global energy consumption, similar to air transport!), as well as substituting for travel, (e.g. Cisco's ultrawideband telepresence system has halved their large worldwide travel budget). This proposal is therefore focused on one of the most important challenges facing our modern society - an energy-efficient, ultra-high capacity ICT infrastructure able to connect people and businesses seamlessly everywhere. Traffic on the global communications infrastructure continues to increase 80% year-on-year, driven by rapidly expanding and increasingly-demanding applications: YouTube, MMS, iPlayer, new concepts such as cloud computing, tele-surgery, the introduction of the iPhone alone proved a severe drain on the capacity of major carriers. Bandwidth growth in the access network is starting to overwhelm the available capacity in the core. In the last 10 years, the number of broadband subscribers worldwide has grown 100-fold. We are now rapidly approaching the fundamental data carrying capacity of current optical technology; moreover, the energy required to support today's growing, power-hungry, ICT infrastructure is looking worryingly unsustainable. It is time to ask hard questions about some long-held assumptions.We propose a radical transformation of the physical infrastructure underpinning today's networks by developing devices capable of 1000-fold improvements in performance, starting with a critical re-examination of some of the most basic transmission building blocks - the optical fibres, amplification and regeneration, and nonlinear switching and distribution. Since the inception of optical telecommunications 40 years ago, the silica fibre has been its work-horse. However, as it nears its capacity limits, a radical rethink can reap dividends in non-linear threshold, transmission window breadth and loss through new materials and designs, leading to 1000-fold improvements. In addition, current power-hungry electronic switches are bottlenecks that photonics can alleviate. Although immensely challenging, the new technologies that we propose have the potential to lead to major advances and benefits in many other important areas - including security, the environment, manufacturing and healthcare. If we are successful in achieving our objectives, the Programme will surely establish the UK firmly as the world leader in optical communications and networking technologies for decades to come.

Photonics is one of six EU "Key Enabling Technologies. The US recently announced a $200M programme for Integrated Photonics Manufacturing to improve its competiveness. As a UK response, the research proposed here will advance the pervasive technologies for future manufacturing identified in the UK Foresight report on the Future of Manufacturing, improving the manufacturability of optical sensors, functional materials, and energy-efficient growth in the transmission, manipulation and storage of data. Integration is the key to low-cost components and systems. The Hub will address the grand challenge of optimising multiple cross-disciplinary photonic platform technologies to enable integration through developing low-cost fabrication processes. This dominant theme unites the requirements of the UK photonics (and photonics enabled) industry, as confirmed by our consultation with over 40 companies, Catapults, and existing CIMs. Uniquely, following strong UK investment in photonics, we include most of the core photonic platforms available today in our Hub proposal that exploits clean room facilities valued at £200M. Research will focus on both emerging technologies having greatest potential impact on industry, and long-standing challenges in existing photonics technology where current manufacturing processes have hindered industrial uptake. Platforms will include: Metamaterials: One of the challenges in metamaterials is to develop processes for low-cost and high-throughput manufacturing. Advanced metamaterials produced in laboratories depend on slow, expensive production processes such as electron beam writing and are difficult to produce in large sizes or quantities. To secure industrial take up across a wide variety of practical applications, manufacturing methods that allow nanostructure patterning across large areas are required. Southampton hosts a leading metamaterials group led by Prof Zheludev and is well positioned to leverage current/future EPSRC research investments, as well as its leading intellectual property position in metamaterials. High-performance special optical fibres: Although fibres in the UV and mid-IR spectral range have been made, few are currently commercial owing to issues with reliability, performance, integration and manufacturability. This platform will address the manufacturing scalability of special fibres for UV, mid-IR and for ultrahigh power sources, as requested by current industrial partners. Integration with III-V sources and packaging issues will also be addressed, as requested by companies exploiting special fibres in laser-based applications. In the more conventional near-infrared wavelength regime, we will focus on designs and processes to make lasers and systems cheaper, more efficient and more reliable. Integrated Silicon Photonics: has made major advances in the functionality that has been demonstrated at the chip level. Arguably, it is the only platform that potentially offers full integration of all the key components required for optical circuit functionality at low cost, which is no doubt why the manufacturing giant, Intel, has invested so much. The key challenge remains to integrate silicon with optical fibre devices, III-V light sources and the key components of wafer-level manufacture such as on line test and measurement. The Hub includes the leading UK group in silicon photonics led by Prof Graham Reed. III-V devices: Significant advances have been made in extending the range of III-V light sources to the mid-IR wavelength region, but key to maximise their impact is to enable their integration with optical fibres and other photonics platforms, by simultaneous optimisation of the III-V and surrounding technologies. A preliminary mapping of industrial needs has shown that integration with metamaterial components optimised for mid-IR would be highly desirable. Sheffield hosts the EPSRC III-V Centre and adds a powerful light emitting dimension to the Hub.