For the UK to reach a net-zero carbon economy, the regulation and limitation of greenhouse gas (GHG) emissions needs to rapidly expand. Natural gas is fast becoming our most dominant fossil fuel and industrial leaks are now a leading source of GHG emissions. Industry majors have committed to expanding emissions monitoring, but the technologies currently available are expensive, labour intensive, and inaccurate. Quantum Gas Imaging (QGI), invented by QLM, is an emerging technology that uses non-cryogenic Shortwave Infrared (SWIR) Single-Photon Avalanche Detectors (SPADs) to demonstrate innovative and highly sensitive long-range, single-photon lidar gas imagers that locate and measure invisible gases including methane, CO2 and more.

The current generation of the QGI camera uses mechanical scanning to analyse an area with a single sensor. This limits the data acquisition rate, thus prohibiting fast mobile deployment, in the interest of maintaining the sensitivity and spatial resolution necessary. Commerical-off-the-shelf (COTS) SPAD arrays can allow for non-mechanical scanning, but current readout electronics are limited in throughput to allow for such developments. SWIR SPAD array readouts, such as these, require high-speed data acquisition. When combined with the flexibility of Field-Programmable Gate-Array (FPGA) technology, this is going to be a key enabling technology for all other photonic 2nd generation quantum technologies based on single-photon quantum optics research, including free-space quantum telecommunications, photonic quantum processors, and lidar.

In this project, QLM Technology will develop a non-mechanical scanning QGI camera that exploits SPAD arrays and their high throughput capabilities to achieve state-of-the-art acquisition rates, sensitivity, and large detector dynamic range. Aston University will develop the advanced signal processing algorithm required to achieve high speed real-time Time to Digital Converter (TDC) and Time-Correlated Single Photon Counting (TCSPC) on FPGAs and utilises multi-photon information for the formation of the correlations. RedWave will build the electronics platform to incorporate the advanced high speed time tagging capability into new standalone products, which can be applied in other fields for the 2nd generation quantum technology used in life science and free-space communications, thanks to the flexibility of the FPGA based system.