Increasing emission levels of air pollution and greenhouse gases (GHGs) in large urban areas have become a great global concern due to their detrimental impact on human health, climate and the entire ecosystem. In order to cut emission levels, mitigation strategies are in place, however, to evaluate the effectiveness of these mitigation measures, the first step will be to improve the air quality (AQ) monitoring networks by deploying high density and high precision sensor networks to accurately capture spatial variability and emission hotspots in real-time. The traditional and more accurate air quality monitoring instrumentation are large, complex and costly, and hence are only sparsely deployed which provide accurate data but only in few locations, not providing enough information to protect the health of the population or to accurately evaluate the mitigation strategies. The emergence of low-cost sensors (LCS) within the last decade enabled observations at high spatial resolution in real-time, however, due to their poor selectivity, their measurement data is highly dependent on atmospheric composition, and also on meteorological conditions that the data generated by these platforms are of poor quality. In this fellowship, I will develop the first low-cost and high precision air pollution monitor based on photonic integrated circuits (PICs) for the next generation air quality monitoring networks. Photonic integration allows hundreds of photonic components to be fabricated on a single chip, and this step-change in technology will deliver a low-cost, on-chip, versatile instrumentation, stabilised to metrological precision that can be deployed in high density networks to accurately monitor a wide range of pollutants within industrial cities with high spatial and temporal resolution. The captured data can be transferred to the cloud servers over the existing mobile networks from which the users can easily monitor air quality with high accuracy at any time and from anywhere. The proposed instrumentation can also be deployed in balloon and satellite missions for in-situ probing of the constituents of the upper atmosphere, aiding the study of complex atmospheric processes to understand its influence on climate change. EPSRC Open Fellowship will enable me to consolidate my expertise gained over the years in industry and academia and gain my research independence. During these five years, I will have established myself to lead a team of 3 -5 researchers and will have enhanced my research output in novel photonic integrated solutions to combat the challenges faced today. This will aid me to be more competitive in applying for traditional Grants to extend my research portfolio and my research team, and become a leader in this field of research. In 10 years, my vision will be to exploit photonic integration technology for wider applications, including medical imaging, material science and non-destructive testing, and provide outstanding training opportunities to research students and early career researchers who will grow to be future academic and industrial leaders in science and engineering in the UK.

The terahertz (THz) frequency region within the electromagnetic spectrum, covers a frequency range of about one hundred times that currently occupied by all radio, television, cellular radio, Wi-Fi, radar and other users and has proven and potential applications ranging from molecular spectroscopy through to communications, high resolution imaging (e.g. in the medical and pharmaceutical sectors) and security screening. Yet, the underpinning technology for the generation and detection of radiation in this spectral range remains severely limited, being based principally on Ti:sapphire (femtosecond) pulsed laser and photoconductive detector technology, the THz equivalent of the spark transmitter and coherer receiver for radio signals. The THz frequency range therefore does not benefit from the coherent techniques routinely used at microwave/optical frequencies. Our programme grant will address this. We have recently demonstrated optical communications technology-based techniques for the generation of high spectral purity continuous wave THz signals at UCL, together with state-of-the-art THz quantum cascade laser (QCL) technology at Cambridge/Leeds. We will bring together these internationally-leading researchers to create coherent systems across the entire THz spectrum. These will be exploited both for fundamental science (e.g. the study of nanostructured and mesoscopic electron systems) and for applications including short-range high-data-rate wireless communications, information processing, materials detection and high resolution imaging in three dimensions.

The sensing, processing and transport of information is at the heart of modern life, as can be seen from the ubiquity of smart-phone usage on any street. From our interactions with the people who design, build and use the systems that make this possible, we have created a programme to make possible the first data interconnects, switches and sensors that use lasers monolithically integrated on silicon, offering the potential to transform Information and Communication Technology (ICT) by changing fundamentally the way in which data is sensed, transferred between and processed on silicon chips. The work builds on our demonstration of the first successful telecommunications wavelength lasers directly integrated on silicon substrates. The QUDOS Programme will enable the monolithic integration of all required optical functions on silicon and will have a similar transformative effect on ICT to that which the creation of silicon integrated electronic circuits had on electronics. This will come about through removing the need to assemble individual components, enabling vastly increased scale and functionality at greatly reduced cost.