This proposal seeks funding to create a Centre for Doctoral Training (CDT) in Connected Electronic and Photonic Systems (CEPS). Photonics has moved from a niche industry to being embedded in the majority of deployed systems, ranging from sensing, biophotonics and advanced manufacturing, through communications from the chip-to-chip to transcontinental scale, to display technologies, bringing higher resolution, lower power operation and enabling new ways of human-machine interaction. These advances have set the scene for a major change in commercialisation activity where electronics photonics and wireless converge in a wide range of information, sensing, communications, manufacturing and personal healthcare systems. Currently manufactured systems are realised by combining separately developed photonics, electronic and wireless components. This approach is labour intensive and requires many electrical interconnects as well as optical alignment on the micron scale. Devices are optimised separately and then brought together to meet systems specifications. Such an approach, although it has delivered remarkable results, not least the communications systems upon which the internet depends, limits the benefits that could come from systems-led design and the development of technologies for seamless integration of electronic photonics and wireless systems. To realise such connected systems requires researchers who have not only deep understanding of their specialist area, but also an excellent understanding across the fields of electronic photonics and wireless hardware and software. This proposal seeks to meet this important need, building upon the uniqueness and extent of the UCL and Cambridge research, where research activities are already focussing on higher levels of electronic, photonic and wireless integration; the convergence of wireless and optical communication systems; combined quantum and classical communication systems; the application of THz and optical low-latency connections in data centres; techniques for the low-cost roll-out of optical fibre to replace the copper network; the substitution of many conventional lighting products with photonic light sources and extensive application of photonics in medical diagnostics and personalised medicine. Many of these activities will increasingly rely on more advanced systems integration, and so the proposed CDT includes experts in electronic circuits, wireless systems and software. By drawing these complementary activities together, and building upon initial work towards this goal carried out within our previously funded CDT in Integrated Photonic and Electronic Systems, it is proposed to develop an advanced training programme to equip the next generation of very high calibre doctoral students with the required technical expertise, responsible innovation (RI), commercial and business skills to enable the £90 billion annual turnover UK electronics and photonics industry to create the closely integrated systems of the future. The CEPS CDT will provide a wide range of methods for learning for research students, well beyond that conventionally available, so that they can gain the required skills. In addition to conventional lectures and seminars, for example, there will be bespoke experimental coursework activities, reading clubs, roadmapping activities, responsible innovation (RI) studies, secondments to companies and other research laboratories and business planning courses. Connecting electronic and photonic systems is likely to expand the range of applications into which these technologies are deployed in other key sectors of the economy, such as industrial manufacturing, consumer electronics, data processing, defence, energy, engineering, security and medicine. As a result, a key feature of the CDT will be a developed awareness in its student cohorts of the breadth of opportunity available and the confidence that they can make strong impact thereon.

The project seeks to take the Athermal Laser research carried out at the University of Cambridge and develop further so that it is at a suitable point for commercial evaluation. The technical develop will involve optimized design, outsourced commercial device prototype fabrication and control hardware and software development. It is anticipated that commercial consultants will be employed to carry out market survey and targeted marketing activities in tandem with Cambridge Enterprise.

Digital-to-Analogue Conversion (DAC) that links the digital domain of '1s' and '0s' to the real-world analogue signals (current and voltage) is an indispensable functionality that enabled the modern ICT. High-speed and high-resolution of DAC, which can generate arbitrary RF signals, is the basis of various applications spanning optical communications, mobile communications, high-definition imaging and the emerging virtual reality. Nevertheless, the realisation of high-speed and high-resolution DAC is extremely challenging due to two reasons. First, there is a trade-off between the resolution (measured by the signal to noise and distortion ratio) and the speed of the DAC. Second, the conventional method of improving DAC speed by reducing the transistor size is now approaching the fundamental limit of electronic fabrication, in which the smallest transistor only contains 10s of atoms. On the other hand, photonics offer over 1000 times more bandwidth resource than conventional radio frequency (RF) electronic device. The substantial technological progress of optoelectronic component in the last decade has enabled a fine control of the amplitude and phase of a lightwave. Photodiode that converts the optical signal to electrical current now can achieve more than 100 Gigahertz frequency range. This project aims to unlock the potential of photonics technologies for future high-speed, high-resolution photonically-synthesized DAC (PhotoDAC) that is capable of generating arbitrary RF signals beyond the bounds of electronic fabrication. This capability will be enabled by a joint innovation of photonics, electronics, and digital signal processing techniques. In this project, the research team will build a prototype DAC instrument using off-the-shelf and customised components. Control software and digital signal processing schemes will be developed to ensure a durable and high-performance DAC prototype. Based on the prototype DAC instrument, the research team will investigate its application in high-speed optical communications, aiming a significantly increased transmission data rate.

It is recognised that global communication systems are rapidly approaching the fundamental information capacity of current transmission technologies. Saturation of the capacity of the communication systems might have detrimental impact on the economy and social progress and public, business and government activities. The aim of the proposed research is to develop, through theory and experiment, disruptive approaches to unlocking the capacity of future information systems that go beyond the limits of current optical communications systems. The research will combine techniques from information theory, coding, study of advanced modulation formats, digital signal processing and advanced photonic concepts to make possible breakthrough developments to ensure a robust communications infrastructure beyond tomorrow. Increasing the total capacity of communication systems requires a multitude of coordinated efforts: new materials and device bases, new fibres, amplifiers and network paradigms, new ways to generate, transmit, detect and process optical signals and information itself - all must be addressed. In particular, the role of fibre communications, providing the capacity for a lion share of the total information traffic, is vital. One of the important directions to avoid the so-called "capacity crunch", the exhaust in fibre capacity - is to develop completely new transmission fibres and amplifiers. However, there is also a growing need for complimentary actions - innovative and radically novel approaches to coding, transmission and processing of information. Our vision is focused on the need to quantify the fundamental limits to the nonlinear channels carried over optical fibres and to develop techniques to approach those limits so as to maximise the achievable channel capacity. The information capacity of a linear channel with white Gaussian noise is well known and is defined by the Shannon limit. Wireless systems can approach this limit very closely - to within fractions of a dB. However, the optical channel is nonlinear. Fibre nonlinearity mixes noise with signal. Therefore, results of the linear theories on capacity can be applied in fibre channels only in the limit of very small nonlinear effects. Optical communication systems are undergoing another revolution with the development of techniques of coherent detection, the ability to detect both the amplitude and the phase of a transmitted signal and use of digital signal processing techniques to reconstruct the original signal. Use of the optical phase in emerging coherent transmission schemes opens up fundamentally new theoretical and technical possibilities most as yet unexplored. The challenge is to understand to what degree optical nonlinearity can also be compensated or, indeed, used to unlock the fibre capacity, maximise both the information transmission rate and the total bandwidth, to determine the fundamental Shannon limit for nonlinear channels and to develop methods to approach this capacity. We propose to explore fundamentally new nonlinear information technologies and to develop a practical design framework based on integration of DSP techniques, novel modulation formats, and novel source and line coding approaches tailored to the nonlinear optical channels. We believe this to be the key to designing the intelligent information infrastructure of the future.

We aim to grow the world's leading centre for training in quantum engineering for the emerging quantum technology (QT) industry. We have designed this CDT in collaboration with a large number of academic and industry experts, and included as partners those who will add substantially to the training and cohort experience. Through this process a consistent picture of what industry wants in future quantum engineers emerged: people who can tackle the hardest intellectual challenges, recognising the end goal of their research, with an ability to move from fundamental physics towards the challenges of engineering and miniaturising practical systems, who understands the capabilities of other people (and why they are useful). Industry wants people with good decision-making, communication and management skills, with the ability to work across discipline boundaries (to a deadline and a budget!) and build interdisciplinary teams, with the ability to translate a problem from one domain to another. Relevant work experience, knowledge of entrepreneurship, industrial R&D operations and business practices are essential. By forming a hub of unrivalled international excellence in quantum information and photonics, surrounded by world-class expertise in all areas of underpinning science and technology and the scientific and technological application areas of QT, and a breadth of academic and industry partners, we will deliver a new type of training: quantum engineering. Bristol has exceptional international activity in the areas that surround the hub: from microelectronics and high performance computing to system engineering and quantum chemistry. The programme will be delivered in an innovative way-focussing particularly on cohort learning-and assessed by a variety of different means, some already in existence in Bristol. We believe that we are attempting something new and exciting that has the potential to attract and train the best students to ensure that the resulting capacity is world-class, thus providing real benefits to the UK economy.