Researchers in IPaQS at Heriot-Watt University have been working within the context of the QuantIC quantum technologies hub to develop a new method to `image at the speed of light’. The used cameras are made of arrays of single photon counters that achieve both single photon sensitivity and picosecond precision measurements of the photon arrival time. They use these to collect and precisely time the very faint return echoes of light, reflected from objects or people that are hidden behind a wall or corner.

For the first ever real time, optical detection and tracking of moving objects, hidden behind an obstacle have been reported. More recently these results are extended to detect also actual humans hidden behind a wall that is more than 50 metres away, thus paving the way towards applications in areas such as surveillance and self-driving cars.

[Nature Photonics 10, 23]