This proposal aims to transition today's highest precision laser technology -- optical frequency combs -- from the lab to the factory, establishing the technique of dual-comb distance metrology as an enabling technology for manufacturing the next generation of precision-engineered products, whose functionality relies on micro-/ nanoscale accuracy. Optical techniques form the basis of critical industrial distance metrology, but face compromises between accuracy, precision and dynamic range. Time-of-flight methods give mm accuracy over an extended range, while interferometric trackers achieve nm precision but with no absolute positional accuracy. By developing novel dual-comb metrology techniques, this project will bridge the gap between precision and extended-range accuracy, providing traceable nm precision, with almost unlimited extended-range operation. For manufacturing industry, comb metrology therefore addresses the important problem of how to verifiably fabricate macro-scale objects with nano-/micro-precision. Building on Heriot-Watt's frequency-comb expertise, we will develop Ti:sapphire and Er:fibre dual combs, with the aim of demonstrating nm-precision controlled-environment metrology using Ti:sapphire, and micron-precision free-space ranging using eye-safe Er:fibre. Besides their novel applications in precision metrology, by implementing new efficient and compact diode-pumping schemes our research will extend laser comb technology in a way that makes these systems suitable for deployment in a wide range of environments outside the research lab, for example as modules in a precision quantum navigation system. Our project integrates key academic and industrial partners who will contribute resources and expertise in lasers (Chromacity), precision micro-optics (Powerphotonic), industrial metrology and manufacturing (Renishaw), ultra-precision metrology (EPSRC Centre for Innovative Manufacturing in Ultra Precision and CDT in Ultra Precision) and applications in large optics for astronomy (STFC UK Astronomy Technology Centre). The commitment of our partners is evidenced by >£300K of support, including £145K of cash which will be used primarily to support two EPSRC EngD and PhD students recruited to the project. The project aligns closely with the EPSRC's Manufacturing the Future challenge theme and the ICT Photonics for Future Systems priority, as well as the EPSRC's training agenda, by engaging EngD and PhD researchers from the CDT in Applied Photonics and the CDT in Ultra Precision. More generally, the project will support the UK's high-precision manufacturing and metrology communities, with potential academic and industrial benefits. By the end of the project we expect to have demonstrated and evaluated dual-comb distance metrology in a variety of practical manufacturing contexts (machine calibration, in-process control, finished-product inspection), and to be in a position to translate the technology into our industrial and academic partners.

The unique properties of light have made it central to our high-tech society. For example, our information-rich world is only enabled by the remarkable capacity of the fibre-optic network, where thin strands of glass are used to carry massive amounts of information around the globe as high-speed optical signals. Light also impacts areas of our society as diverse as laser-based manufacturing, solar energy, space-based remote sensing and even astronomy. One area where the properties of light open up otherwise-impossible capabilities is medicine. In ophthalmology for example, lasers are routinely used to perform surgery on the eye through corneal reshaping. This involves two different lasers. In the first step, a laser producing very short pulses of infrared light cuts a flap in the front surface of the eye to provide access. In the second step, another laser producing longer pulses of ultraviolet (UV) light sculpts the shape of the cornea and correct focusing errors. The flap is then folded back into place so that the cornea can heal. The two very-different laser systems in that example illustrate an important point: the effects of light on human tissues are highly-dependent on the specific properties of both the light and the tissues involved. To sculpt the cornea, the laser wavelength of 193 nm is in the deep UV region of the electromagnetic spectrum, much shorter than the visible range (380 - 740 nm) we are familiar with. This is because (unlike visible light) it is very efficiently absorbed by the cornea, so that essentially all the energy of the light is deposited at the surface. Thus only a very thin layer of tissue (a few microns thick) is removed, or "resected", with each pulse of light, facilitating very-precise shaping of the cornea and accurate adjustment of its focusing properties. 193 nm light can be generated by an ArF excimer gas laser, a >40 year-old technology producing a poor-quality low-brightness beam of light. This is suitable for corneal reshaping, but not for a range of other important therapies requiring higher-quality deep UV beams. Unfortunately, alternative ways to generate such short wavelengths are non-trivial, resulting in complex and expensive laser systems not suitable for widespread clinical uptake. U-care aims to address this gap by exploiting cutting-edge techniques in laser physics. We will develop new sources of deep UV light which will be highly compact, robust and low cost. We will develop ways to deliver this light precisely to tissues, and work to understand in detail the biophysical mechanisms involved. Our efforts will focus on new therapies that target some of the biggest challenges facing medicine: cellular-precision cancer surgery, and the emergence of drug-resistant "super-bugs". Importantly, U-care will involve engineers and physical scientists working in close collaboration with clinicians and biomedical scientists to verify that the therapies we develop are effective and safe. By doing so in an integrated manner, we will drive our deep-UV light therapies towards healthcare impact and widespread use in the clinic by 2050.

In a consortium led by Heriot-Watt with St Andrews, Glasgow, Strathclyde, Edinburgh, Dundee, Huddersfield and NPL, the "EPSRC CDT in Use-Inspired Photonic Sensing and Metrology" responds to the focus area of "Meeting a User-Need and/or Supporting Civic Priorities" and aligns to EPSRC's Frontiers in Engineering & Technology priority and its aim to produce "tools and technologies that form the foundation of future UK prosperity". Our theme recognises the key role that photonic sensing and metrology has in addressing 21st century challenges in transport (LiDAR), energy (wind-turbine monitoring), manufacturing (precision measurement), medicine (disease sensors), agri-food (spectroscopy), security (chemical sensing) and net-zero (hydrocarbon and H2 metrology). Building on the success of our earlier centres, the addition of NPL and Huddersfield to our team reflects their international leadership in optical metrology and creates a consortium whose REF standing, UKRI income and industrial connectivity makes us uniquely able to deliver this CDT. Photonics contributes £15.2bn annually to the UK economy and employs 80,000 people--equal to automotive production and 3x more than pharmaceutical manufacturing. By 2035, more than 60% of the UK economy will rely on photonics to stay competitive. UK companies addressing the photonic sensing and metrology market are therefore vital to our economy but are threatened by a lack of doctoral-level researchers with a breadth of knowledge and understanding of photonic sensing and metrology, 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 this high-growth, export-led sector whose products and services have far-reaching impacts on our society. The proposed CDT will train 55 students. These will comprise at least 40 EngD students, characterised by a research project originated by a company and hosted on their site. A complementary stream of up to 15 PhD students will pursue industrially relevant research in university labs, with more flexibility and technical risk than in an EngD project. In preparing this bid, we invited companies to indicate their support, resulting in £5.5M cash commitments for 102 new students, considerably exceeding our target of 55 students, and highlighting industry's appetite for a CDT in photonic sensing and metrology. Our request to EPSRC for £6.13M will support 35 students, with the remaining students funded by industrial (£2.43M) and university (£1.02M) cash contributions, translating to an exceptional 56% cash leverage of studentship costs. The university partners provide 166 named supervisors, giving the flexibility to identify the most appropriate expertise for industry-led EngD projects. These academics' links to >120 named companies also ensure that the networks exist to co-create university-led PhD projects with industry partners. Our team combines established researchers with considerable supervisory experience (>50 full professors) with many dynamic early-career researchers, including a number of prestigious research fellowship holders. A 9-month frontloaded residential phase in St Andrews and Edinburgh will ensure the cohort gels strongly, equipping students with the knowledge and skills they need before starting their research projects. These core taught courses, augmented with electives from the other universities, will total 120 credits and will be supplemented by accredited MBA courses and training in outreach, IP, communication skills, RRI, EDI, sustainability and trusted-research. Collectively, these training episodes will bring students back to Heriot-Watt a few times each year, consolidating their intra- and inter-cohort networks. Governance will follow our current model, with a mixed academic-industry Management Committee and an International Advisory Committee of world-leading experts.

Approximate 30% of the emissions of e-vehicles comes from the manufacturing processes, due to un-optimised material utilisation, low process efficiency, product defects and waste. Current state-of-the-art identifies laser material processing technologies the heart of e-vehicles manufacturing. Advances in laser technologies and new generation scanning optics in fuel cell and battery manufacturing have the potential to offer enhanced utilisation of materials, improved process efficiency and product quality, allowing significant reduction in CO2 equivalent. Lasers4NetZero will establish an innovative training programme that aims at coaching a new generation of creative, entrepreneurial and innovative doctoral candidates (PhDs) focused on laser material processing, artificial intelligence for quality control, advanced process simulation and predictive lifecycle and sustainability analysis for e-vehicles manufacturing. This novel programme will contain both scientific and transferable training activities and will benefit from training across the network (e.g. secondments). In total, 10 PhDs will be enrolled, developing individual research projects within the project. Individual PhD projects will integrate novel methods and approaches for laser material processing (cutting and welding) aided by laser beam shaping and ultra-fast scanning technologies with the ultimate goal to enhance utilisation of materials, improve process efficiency and product quality and reduce defects and waste. The consortium involves 6 Academic partners and 8 Industrial partners guaranteeing that final solutions will be close to the market. The close cooperation among multidisciplinary partners will ensure knowledge transfer to cross the valley-of-death between research and implementation. To maximise impact, two demonstrators (fuel cells and battery systems) will be developed in conjunction with the Industrial partners.

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.