The co-existence of data transmission and lighting inside a common light emitting diode (LED) to complement the radio frequency based wireless communication in satisfying the global socio-economic activities is a low-cost/low-energy proposition termed visible light communications (VLC). It radically turns a passive light source into a dynamic service hub that provides opportunities to improve existing services and introduce new ones. For this nascent VLC idea to gain traction and realise its huge potential however, vital optimisation approach to mutually accommodate data and illumination on the same LED becomes a necessity. This includes studying, understanding and quantifying the inter-relationship between lighting requirements and data transmission as against the current approach that completely disregards this. To this end, this research will be investigating the impacts of VLC on the fundamental properties of energy efficiency, light quality and life expectancy of an LED that is primarily designed for lighting/display. The findings from this work will provide the required approach for optimising VLC and safeguard the LED's reliability, durability and emitted light quality

In the near future, light emitting diodes (LEDs) will replace all other sources of light - from the lamps that light homes and offices to the headlights of cars. As well as providing illumination, these LEDs can be used to transmit data, and so offer an opportunity to create a new wireless infrastructure for data transmission. The demand for wireless communications to smartphones, watches, tablets and other devices is growing at a rate of 50% per year, and new technologies are needed to augment the capacity of conventional WiFi. Using LEDs in visible light communications offers a huge potential capacity to support this growth and to provide new services that use localised wireless communications. While LEDs can transmit the information, an optical receiver is needed to collect the transmitted light, convert it to an electrical signal and extract the transmitted data. The maximum amount of light that can be transmitted is limited by the illumination brightness and concerns for the eye safety and comfort of users. The sensitivity of the receiver therefore ultimately determines the range over which optical data can be transmitted and/or the maximum possible data rate. The sensitivity of existing receivers for visible light communications is limited by a combination of the methods used to collect light and the devices used to convert this light to an electrical signal. In this project we aim to create new super receivers that are significantly more sensitive than existing optical receivers; that overcome conventional limits for combining speed, sensitivity and easy alignment; that are thin and flexible enough to be easily integrated onto any device. A dramatic change in performance will be achieved by combining two technologies- fluorescent concentrators and arrays of single-photon avalanche photodiodes- in a receiver for the first time. The first will use fluorescent materials to absorb the transmitted light signal and re-emit it at a different wavelength onto the detector. Using this method we will collect light over large areas using a thin, flexible layer which guides and concentrates the emitted light to its edges. The second technology is a light detector capable of detecting individual photons. We will develop methods to count photons from the transmitter in the presence of ambient light. We will explore how to optimise the fluorescent materials and light collecting layer to efficiently concentrate light onto one or more light detectors, and develop methods to maximise the amount of data transmitted by optimising how the data is represented. These super receivers will be tested in free-space visible light communications links to quantify their performance. Our estimates suggest that this approach could lead to a 100 times improvement in performance over current receivers, enabling faster data transmission, longer transmission ranges and the ability to operate in difficult environments, such as in the presence of bright ambient light.

Future information and communication networks will certainly consist of both classical and quantum devices, some of which are expected to be dishonest, with various degrees of functionality, ranging from simple routers to servers executing quantum algorithms. The realisation of such a complex network of classical and quantum communication must rely on a solid theoretical foundation that, nevertheless, is able to foresee and handle the intricacies of real-life implementations. The study of security, efficiency and verification of quantum communication and computation is inherently related to the fundamental notions of quantum mechanics, including entanglement and non-locality, as well as to central notions in classical complexity theory and cryptography. The central Research objective of our proposal is an end to end investigation of the verification and validation of quantum technologies, from full scale quantum computers and simulators to communication networks with devices of varying size and complexity down to realistic ``quantum gadgets". This goal represents a key challenge in the transition from theory to practice for quantum computing technologies. We will work closely with experimentalists and engineers to ensure that theoretical progress takes Development considerations into account, and will design prototypes for proof-of-principle demonstrations of our methods. The experimental aspects of our proposal are supported by the PI's associate directorial position at the Oxford led hub, joint projects with the York led hub as well as other ongoing collaborations with experimental labs in France and Austria. Meanwhile the required expertise in engineering design would be supported through a new collaboration of the PI as part of the Edinburgh Li-Fi research and development centre. The Deployment axis, complementing our core activity in research-development, will be built upon the unique Edinburgh entrepreneurial culture supported by Informatics Ventures as well as a dedicated senior business advisory board (which sponsored the PI's recent patent on quantum cloud). Advances to the problem of secure delegated computation would have an immediate significant consequence on how computational problems are solved in the real world. One can envision virtually unlimited computational power to end users on the go, using just a simple terminal to access the computing cloud which would turn any smartphone into a quantum-enhanced phone. This will generate new streams of growth for the UK cyber security sector as well as complementary business developments for the National quantum technology investment.

Given the unprecedented demand for mobile capacity beyond that available from the RF spectrum, it is natural to consider the infrared and visible light spectrum for future terrestrial wireless systems. Wireless systems using these parts of the electromagnetic spectrum could be classified as nmWave wireless communications system in relation to mmWave radio systems and both are being standardised in current 5G systems. TOWS, therefore, will provide a technically logical pathway to ensure that wireless systems are future-proof and that they can deliver the capacities that future data intensive services such as high definition (HD) video streaming, augmented reality, virtual reality and mixed reality will demand. Light based wireless communication systems will not be in competition with RF communications, but instead these systems follow a trend that has been witnessed in cellular communications over the last 30 years. Light based wireless communications simply adds new capacity - the available spectrum is 2600 times the RF spectrum. 6G and beyond promise increased wireless capacity to accommodate this growth in traffic in an increasingly congested spectrum, however action is required now to ensure UK leadership of the fast moving 6G field. Optical wireless (OW) opens new spectral bands with a bandwidth exceeding 540 THz using simple sources and detectors and can be simpler than cellular and WiFi with a significantly larger spectrum. It is the best choice of spectrum beyond millimetre waves, where unlike the THz spectrum (the other possible choice), OW avoids complex sources and detectors and has good indoor channel conditions. Optical signals, when used indoors, are confined to the environment in which they originate, which offers added security at the physical layer and the ability to re-use wavelengths in adjacent rooms, thus radically increasing capacity. Our vision is to develop and experimentally demonstrate multiuser Terabit/s optical wireless systems that offer capacities at least two orders of magnitude higher than the current planned 5G optical and radio wireless systems, with a roadmap to wireless systems that can offer up to four orders of magnitude higher capacity. There are four features of the proposed system which make possible such unprecedented capacities to enable this disruptive advance. Firstly, unlike visible light communications (VLC), we will exploit the infrared spectrum, this providing a solution to the light dimming problem associated with VLC, eliminating uplink VLC glare and thus supporting bidirectional communications. Secondly, to make possible much greater transmission capacities and multi-user, multi-cell operation, we will introduce a new type of LED-like steerable laser diode array, which does not suffer from the speckle impairments of conventional laser diodes while ensuring ultrahigh speed performance. Thirdly, with the added capacity, we will develop native OW multi-user systems to share the resources, these being adaptively directional to allow full coverage with reduced user and inter-cell interference and finally incorporate RF systems to allow seamless transition and facilitate overall network control, in essence to introduce software defined radio to optical wireless. This means that OW multi-user systems can readily be designed to allow very high aggregate capacities as beams can be controlled in a compact manner. We will develop advanced inter-cell coding and handover for our optical multi-user systems, this also allowing seamless handover with radio systems when required such as for resilience. We believe that this work, though challenging, is feasible as it will leverage existing skills and research within the consortium, which includes excellence in OW link design, advanced coding and modulation, optimised algorithms for front-haul and back-haul networking, expertise in surface emitting laser design and single photon avalanche detectors for ultra-sensitive detection.

The rapidly developing technique of transfer printing on the micro and nanoscales allows the manufacture of high quality, high performance devices on a wide range of substrates in almost any location. This highly versatile capability features a high-precision mechanical pick-and-place assembly technique that utilises the adhesive properties of soft stamps, and the technology has only recently broken into the field of electronics and photonics. Placing this exciting and highly important development into context, in the 1990s Whitesides (Harvard University Chemistry Dept.), a pioneer in microfabrication and nanotechnology, established the ground-breaking concept of patterning self-assembled monolayers for lithographic, sensing, medical and pharmaceutical applications and termed this micro-contact printing. From this foundation, the technique has evolved into much higher levels of complexity in which micro-transfer printing has recently delivered micro- LED arrays that, for example, feature in flexible displays and provide inorganic analogues of flexible organic light-emitting diodes (OLEDs) - something that was previously thought to be extremely challenging if not impossible. In this programme, 'Hetero-print', we aim to rapidly push this exciting field further by establishing, for the first time and ahead of the international competition, new routes towards the manufacture of heterogeneous devices, consisting of integrated systems made from pure and/or hybrid inorganic/organic materials. The demand for these hybrid approaches is extremely high, because it opens up the prospect of multifunctional devices that organic materials can deliver in tandem with inorganic semiconductor technology. The ambition of Hetero-print is to deliver micro- and nano-transfer printing as the technology for the versatile and scalable manufacture of heterogeneous materials, structures and devices. In achieving this, we will introduce significant new capabilities for the manufacture of electronic, photonic, and other systems, which complement and are synergistic with those of established semiconductor mass-manufacturing methods including vacuum deposition and solution processing. In this respect, transfer printing is a highly scalable technique and perfectly suited to high volume manufacture, allowing >10,000 micro-sized integrated circuits to be processed in a single run. An issue with many photonic devices is cost, but micro-transfer printing can be economical with the number of print cycles from a single stamp running into the tens of thousands; the technique is also economical in terms of materials waste, providing a methodology to manufacture multiple-array devices in very high yield.