Light is essential for life. For example, light is key to photosynthesis and vision. Light is also important in technology, such as in nanoscale optoelectronic devices. Developing a molecular-level understanding of light-induced processes is crucial for the rational design of new light-activated materials to address important challenges currently facing society, such as harnessing solar energy efficiently and developing new tools for disease diagnosis and therapeutics. Our vision is to establish a unique, state-of-the-art, laser facility providing femtosecond light pulses with a wide range of energies, from the infrared (IR) to the vacuum ultraviolet (VUV), housed in a £2M purpose-built, environmentally-controlled, stable basement laboratory. We will exploit this facility to improve our fundamental understanding of light-induced processes by using a bottom-up approach to study systems across the complexity scale, from isolated gas-phase molecules to proteins, nanoparticles, soft materials and solids, for applications ranging from bioimaging and therapeutics to solar energy materials. This will be achieved using a single spectroscopic technique, time-resolved photoelectron spectroscopy, in molecular and ion beams, liquid-microjets and surfaces, complemented by femtosecond transient absorption spectroscopy, femtosecond stimulated Raman spectroscopy and multi-photon microscopy.

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.

In a consortium led by Heriot-Watt with St Andrews, Glasgow, Strathclyde, Edinburgh and Dundee, this proposal for an "EPSRC CDT in Industry-Inspired Photonic Imaging, Sensing and Analysis" responds to the priority area in Imaging, Sensing and Analysis. It recognises the foundational role of photonics in many imaging and sensing technologies, while also noting the exciting opportunities to enhance their performance using emerging computational techniques like machine learning. Photonics' role in sensing and imaging is hard to overstate. Smart and autonomous systems are driving growth in lasers for automotive lidar and smartphone gesture recognition; photonic structural-health monitoring protects our road, rail, air and energy infrastructure; and spectroscopy continues to find new applications from identifying forgeries to detecting chemical-warfare agents. UK photonics companies addressing the sensing and imaging market are vital to our economy (see CfS) but their success is threatened by a lack of doctoral-level researchers with a breadth of knowledge and understanding of photonic imaging, sensing and analysis, coupled with high-level business, management and communication skills. By ensuring a supply of these individuals, our CDT will consolidate the UK industrial knowledge base, driving the high-growth export-led sectors of the economy whose photonics-enabled products and services have far-reaching impacts on society, from consumer technology and mobile computing devices to healthcare and security. Building on the success of our CDT in Applied Photonics, the proposed CDT will be configured with most (40) students pursuing an EngD degree, characterised by a research project originated by a company and hosted on their site. Recognizing that companies' interests span all technology readiness levels, we are introducing a PhD stream where some (15) students will pursue industrially relevant research in university labs, with more flexibility and technical risk than would be possible in an EngD project. Overwhelming industry commitment for over 100 projects represents a nearly 100% industrial oversubscription, with £4.38M cash and £5.56M in-kind support offered by major stakeholders including Fraunhofer UK, NPL, Renishaw, Thales, Gooch and Housego and Leonardo, as well as a number of SMEs. Our request to EPSRC for £4.86M will support 35 students, from a total of 40 EngD and 15 PhD researchers. The remaining students will be funded by industrial (£2.3M) and university (£0.93M) contributions, giving an exceptional 2:3 cash gearing of EPSRC funding, with more students trained and at a lower cost / head to the taxpayer than in our current CDT. For our centre to be reactive to industry's needs a diverse pool of supervisors is required. Across the consortium we have identified 72 core supervisors and a further 58 available for project supervision, whose 1679 papers since 2013 include 154 in Science / Nature / PRL, and whose active RCUK PI funding is £97M. All academics are experienced supervisors, with many current or former CDT supervisors. An 8-month frontloaded residential phase in St Andrews and Edinburgh will ensure the cohort gels strongly, and will equip students with the knowledge and skills they need before beginning their research projects. Business modules (x3) will bring each cohort back to Heriot-Watt for 1-week periods, and weekend skills workshops will be used to regularly reunite the cohort, further consolidating the peer-to-peer network. Core taught courses augmented with specialist options will total 120 credits, and will be supplemented by professional skills and responsible innovation training delivered by our industry partners and external providers. Governance will follow our current model, with a mixed academic-industry Management Committee and an independent International Advisory Board of world-leading experts.

Ti:sapphire lasers set the standard for precision in instrumentation. However, commercial systems are bulky and complex to make, due in large part to the requirement for a painstakingly manufactured pump laser. The potential exists to replace these complex pump lasers with mass-produced, compact, and inexpensive diode lasers if we can unpick the physics of the light-matter interactions that govern the efficiency. This programme will lead to a step-change in our understanding, allowing us to redesign Ti:sapphire lasers from the ground up, tailoring them for diode-pumping and enabling high-end applications beyond the laser lab, initially in portable quantum technologies and analytical instrumentation. This project will - - Fully describe the underlying physics of pump-induced losses in Ti:sapphire crystals for the first time. - Initiate the development of a manufacturable, platform laser technology with the performance of Ti:sapphire but the practicality of diode-pumping. - Identify the combinations of diode-laser and Ti:sapphire crystal specification required to maximise both the wall-plug efficiency and manufacturability of Ti:sapphire lasers. - Develop exemplar narrow-linewidth and dual-comb demonstrators for future development towards applications in optical clocks and combustion analysis. The investigator team for this project brings together the grouping that demonstrated the first diode-pumped Ti:sapphire laser with experts in narrow-linewidth lasers for quantum technologies and laser spectroscopy for combustion analysis. The project partners include one of the world's leading manufactures of high-specification lasers (Coherent Scotland), the world's leading manufacturer of Ti:sapphire crystals (GTAT Corporation), a high-power visible diode-laser systems manufacturer (Arctos Lasertechnik), and the UK National Quantum Technologies Hub for Sensors and Metrology. An advisory panel of representative for these organisations, together with experts on technology transfer in the manufacturing of lasers and industrial gas-sensing, will provide the investigator team with strong industrial guidance and a route to accelerate economic and societal impact.

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.