I propose a new approach to supplying technologies for the last-mile global communication networks. High-speed data links are central to an ever-more integrated digital economy where, every day, more and more data is shared on our already over-stretched communications networks. A key challenge is the development of new high-bandwidth, secure communication networks, particularly through the internet. The online multimedia services we use on a daily basis are huge users of network bandwidth. With the number of multimedia users in the UK increasing on a monthly basis, the result is a huge drain on the available network bandwidth. Even in standard definition, watching our favourite TV show uses around 1GB of data per hour (and 3GB per hour for high definition). Beyond multimedia, as cloud-based storage and computing becoming the norm establishing high-bandwidth communication networks will be vital. Core backbone communication networks are regularly upgraded to deal with these demands, however the last-mile network, which takes our Internet services to homes and offices, is difficult and expensive to upgrade. This difficulty arises from the distributed nature of this portion of the network and solutions for cost effective, and sustainable, upgrades are required to be commercially deployed over the next 5-10 years. This project the aims to develop solutions to implementation of high-speed free-space last-mile networks. Using light beams carrying Orbital Angular Momentum, a single point-to-point link will increase the number of data carrying channels. Using orbital angular momentum in this way is an example of spatial multiplexing. These multiplexing techniques have the potential to offer multiplicative increases in data rates whilst simultaneously increasing the security of the link. A key deliverable will be the development of a last-mile building to building link within our new campus, for the development and testing of prototype novel multiplexing and de-multiplexing technology. Working with Industrial partners Intel and Corning, solutions will be developed in line with their market requirement, allowing near-term commercial uptake. These industry inspired challenges raise some questions about the fundamental nature of long distance propagation of spatial modes. Hence, along with overcoming the technical hurdles this project aims to investigate the effect of turbulence within the free-space propagation of spatially multiplexed beams. In the early stages of this project, studies into the optical aberrations, and modal cross coupling will be carried out in different environmental settings. This vital data will provide a base to design and develop passive, and active approaches to overcoming the limitations imposed by atmospheric turbulence. Further to these challenges, techniques to allow integration into current installed fibre networks will be developed. The proof-of-principle link will allow real life user testing, where standard internet services will be demonstrated over the link, aiming to providing a commercially viable last-mile link design as a key deliverable of the project.

Photovoltaic (PV) devices convert sunlight directly into electricity and form an increasingly important part of the global renewable energy landscape. Today's PVs are based on conventional semiconductors which are energy-intensive to produce and restricted to rigid flat plate designs. The next generation of PVs will be based on very thin films of semiconductors that can be processed from solution at low temperature, which opens the door to exceptionally low cost manufacturing processes and new application areas not available to today's rigid flat plate PVs, particularly in the areas of transportation and buildings integration. The emerging generation of thin film PVs also offer exceptional carbon dioxide mitigation potential because they are expected to return the energy used in their fabrication within weeks of installation. However, this potential can only be achieved if the electrode that allows light into these devices is low cost and flexible, and at present no electrode technology meets both the cost constraint and technical specifications needed. This proposal seeks to address this complex and inherently interdisciplinary challenge using three new and distinct approaches based on the use of nano-structured films of metal less than 100 metal atoms in thickness. The first approach focuses on the development of a low cost, large area method for the fabrication of metal film electrodes with a dense array of holes through which light can pass unhindered. The second approach seeks to determine design rules for a new type of 'light-catching' electrode that interacts strongly with the incoming light, trapping and concentrating it at the interface with the semiconductor layer inside the device responsible for converting the light into electricity. The final approach is based on combining ultra-thin metal films with ultra-thin films of transparent semiconductor materials to achieve double layer electrodes with exceptional properties resulting from spontaneous intermixing of the two thin solid films. The UK is a global leader in the development of next generation PVs with a growing number of companies now focused on bringing them to market, and so the outputs of the proposed programme of research has strong potential to directly increase the economic competitiveness of the UK in this young sector and would help to address the now time critical challenge of climate change due to global warming.

This proposal brings together experts in complementary areas of physics, chemistry and engineering, to explore new science with potentially high practical impact. Processing glass and similar materials to precise, polished surfaces is the "hidden gem" behind many products and services we take for granted - both in precise control of the distribution of light (e.g. anti-glare headlamps), or to focus light in imaging. From medical X-ray cameras to satellite optics, precise, smooth surfaces are required, with surface errors but small fractions of a micron (maybe 1/1000 the width of a human hair), with roughness down to a few atoms. Also, highly localised defects can scatter light, reducing contrast, or lead to component failure in high-power laser applications. Polishing 'rubs' surfaces to remove damage from prior hard-grinding, and then controls surface-contours to meet design requirements. Historically, these steps were performed by highly-skilled craftspeople, who are in ever-shorter supply as they retire. Modern CNC machines now take much of the drudgery out, but even so, multiple polish/measure cycles are needed to reach refined levels of quality. The basic reason is that, after some 400 years of optical manufacture, the underlying 'rubbing' processes are still far from perfectly understood. A practical setup typically deploys some kind of rotating tool, fed with a liquid slurry containing a fine abrasive powder. The tool moves over a glass surface, often with complex contours. Details of fluid-flow at the microscopic level between tool and glass are complex, and control local interactions of individual abrasive particles with the glass. Then, at the atomic ('nano') scale, chemical-attack, plastic-flow and brittle-fracture perform a complex 'dance', controlling how material is removed. Prior work at various institutions has tended to focus on fluid flow OR nano-scale removal, representing distinct disciplines. But, modelling fluid-flow alone (computational fluid dynamics) omits chemistry and fracture-mechanics. Conversely, nano-scale molecular dynamics omits important fluid-flow issues. What nobody has done before, as we propose, is to combine these distinct approaches, supported by real-time process-monitoring data, and high-performance computing. Then CFD can provide molecular dynamics with predicted particle-trajectories, and particles in CFD can be treated as chemically-reactive rather than inert. The models can then by brought together in a unified large-scale and predictive macro model of removal-processes. Often, scientific breakthroughs arise at the INTERFACES between disciplines - precisely where this proposal focusses. This model will be further developed through polishing trials of complete surfaces, drawing on real-time process-data to predict removal, and post-process measurement of what material has been removed where, plus any defects. This promises to reveal how a surface progresses in real-time, when it is smothered with slurry and invisible to direct inspection. Processes can then be tuned 'on the fly' to keep removal on-target, and improve accuracy of the result. Our aim is then to reduce the number of process cycles required, and give insight into why defects arise and how to control them. In implementing the above, the mathematical and computer models developed at nano, micro and macro scales will describe fundamental aspects of molecules and fluids. This will be generally applicable, including different materials and abrasives. Another important application arises where the methods could be transformative - processes underlying materials wearing in mechanical systems (bearings, slide-ways, human joint-implants etc). So, what starts out as fundamental research into "intentional wear" in processes such as polishing, promises to have a profoundly significant impact on our understanding and control of "incidental wear" in things that rub - and wear-out - in everyday life!

Optical networks underpin the global digital communications infrastructure, and their development has simultaneously stimulated the growth in demand for data, and responded to this demand by unlocking the capacity of fibre-optic channels. The work within the UNLOC programme grant proved successful in understanding the fundamental limits in point-to-point nonlinear fibre channel capacity. However, the next-generation digital infrastructure needs more than raw capacity - it requires channel and flexible resource and capacity provision in combination with low latency, simplified and modular network architectures with maximum data throughput, and network resilience combined with overall network security. How to build such an intelligent and flexible network is a major problem of global importance. To cope with increasingly dynamic variations of delay-sensitive demands within the network and to enable the Internet of Skills, current optical networks overprovision capacity, resulting in both over- engineering and unutilised capacity. A key challenge is, therefore, to understand how to intelligently utilise the finite optical network resources to dynamically maximise performance, while also increasing robustness to future unknown requirements. The aim of TRANSNET is to address this challenge by creating an adaptive intelligent optical network that is able to dynamically provide capacity where and when it is needed - the backbone of the next-generation digital infrastructure. Our vision and ambition is to introduce intelligence into all levels of optical communication, cloud and data centre infrastructure and to develop optical transceivers that are optimally able to dynamically respond to varying application requirements of capacity, reach and delay. We envisage that machine learning (ML) will become ubiquitous in future optical networks, at all levels of design and operation, from digital coding, equalisation and impairment mitigation, through to monitoring, fault prediction and identification, and signal restoration, traffic pattern prediction and resource planning. TRANSNET will focus on the application of machine techniques to develop a new family of optical transceiver technologies, tailored to the needs of a new generation of self-x (x = configuring, monitoring, planning, learning, repairing and optimising) network architectures, capable of taking account of physical channel properties and high-level applications while optimising the use of resources. We will apply ML techniques to bring together the physical layer and the network; the nonlinearity of the fibres brings about a particularly complex challenge in the network context as it creates an interdependence between the signal quality of all transmitted wavelength channels. When optimising over tens of possible modulation formats, for hundreds of independent channels, over thousands of kilometres, a brute force optimisation becomes unfeasible. Particular challenges are the heterogeneity of large scale networks and the computational complexity of optimising network topology and resource allocation, as well as dynamical and data-driven management, monitoring and control of future networks, which requires a new way of thinking and tailored methodology. We propose to reduce the complexity of network design to allow self-learned network intelligence and adaptation through a combination of machine learning and probabilistic techniques. This will lead to the creation of computationally efficient approaches to deal with the complexity of the emerging nonlinear systems with memory and noise, for networks that operate dynamically on different time- and length-scales. This is a fundamentally new approach to optical network design and optimisation, requiring a cross-disciplinary approach to advance machine learning and heuristic algorithm design based on the understanding of nonlinear physics, signal processing and optical networking.

Metal-organic frameworks (MOFs) are three-dimensional structures composed of inorganic nodes, connected by organic linkers. The ease at which different elements or functionalities can be incorporated into a plethora of nanoscopic architectures has led to the population of an enormous class of compounds. Over 60,000 crystalline structures have been reported, which can be 'tuned' to exhibit exceptional selectivity for pre-determined target guest molecules. Two products, from companies span out of Northwestern and Queen's University Belfast, have been commercialised, in the areas of toxic gas storage and fruit packaging. Furthermore, huge societal and economic benefits from their use in highly selective CO2 capture, drug delivery, chemical sensing, toxic gas separations and harmful waste storage applications have been proposed, though not delivered. This is partly due to the gap between the significant strides made in chemical synthesis, and a dearth of work on their physical properties. It is therefore highly surprising that even the most basic of all physical properties, the state of matter, represents one of the most under-researched areas in the MOF field. This proposal hence aims at addressing this bias towards the ordered, crystalline solid domain, which is vital given the research invested into the field and the potential benefits from the combination of the mechanical stability of the amorphous domain, with the chemical opportunities afforded by MOFs. The recent discovery of the glass-forming ability of the MOF family offers the tantalising prospect of accurately designing functional glasses by first tuning the chemical properties of the parent crystalline framework, prior to subsequent melting and liquid quenching. The transfer of functionality from crystal to glass in this manner will enable the next generation of a plethora of functional glasses to be produced. Such materials will lie at the forefront of efforts to move MOFs away from the current focus on the crystalline porous state. Two new classes of functional MOF-glasses will be produced in the course of the project; (i) porous MOF-glasses for separations and (ii) chiral MOF glasses for advanced optical applications. With respect to the former, the development of porous MOF-glasses or MOF-glass composite membranes for gas separations would prove a significant advancement in the field, given the current mixed matrix membranes suffer from chemical compatibility problems and a reduction in active component. In addition, reactions between MOFs in the liquid phase will be studied, and the structure and properties of the resultant multicomponent glasses produced investigated. The 'soft' nature of MOFs also leads to the structural collapse of some frameworks during the post-processing processes (e.g. sintering, ball-milling, pelletisation) used to convert nano-crystalline powders to industrially useable morphologies. The development of a variety of morphologies (i.e. thin films, beads, and self-supporting, binder-free membranes from microcrystalline powders is therefore absolutely essential for the field to move forwards to application. Concentrating on both fundamentally expanding our basic understanding of the field and at the same time bridging the gap between basic science and industrial relevance, this project is highly interdisciplinary in nature. The overarching aims of this proposal are thus to; (i) create new porous and chiral MOF-glasses (ii) create new composite materials for separation by combining crystalline MOFs and their glassy counterparts, (iii) produce a binary phase diagram for the reaction of two MOF liquids and analyse the products formed and (iv) cross-link unstable MOF spheres produced in previous work by the group, and extend the methodology to another MOF family.