Scientists at Heriot-Watt University in Edinburgh have developed a camera that can scatter laser light around corners, and then detect its bounceback at 20bn frames a second to track its movement like a sonar echo.
Genevieve Gariepy, a PhD researcher in Heriot-Watt University’s extreme light group, said: “The system works by sending light from the camera towards the hidden object or person, and getting it back again.
“A laser sends short pulses of light that last for one hundredth of a trillionth of a second onto the floor in front of the corner of the wall. The light hits the floor, scatters, and travels in every direction, like a growing sphere of light.
“The light then bounces off the object, like an echo, and is sent back to the camera.
“By measuring the time it takes to return to the camera, we know how far away the object is. By recording the shape of the laser ‘echo’, we know what direction it’s coming from. It takes only a second for the camera to record all of this: so if the object is moving, we can follow it.”
Professor Daniele Faccio, from Heriot-Watt University, said: “The ability to detect the 3D shape of static, hidden objects has been demonstrated before, but the long acquisition time required by existing methods meant locating and monitoring the objects was a major challenge.
“We can now track hidden objects in real time and we’re still making discoveries about how the light identifies the objects, and can picture them in considerable detail.
“We’ve already increased the distance from which the camera system will work, which is over several metres. We’re also focusing on how we could attempt 3D reconstruction of the objects captured by the camera.”
Installing the technology in cars would mean that drivers would be notified about moving objects hidden from view, when walls or lorries are obscuring visibility.
The technology also has applications in situations when rescue teams need to assess whether it’s safe to enter a room or building.
The research will be published in the journal Nature Photonics this week.