A camera that uses laser light to see around corners in real time has been developed by Scottish researchers who say it will improve road safety.
Unlike previous devices capable of seeing around corners, the new camera designed by a team from Heriot-Watt University in Edinburgh doesn’t take long to create an image and is thus the first that has demonstrated practical use in real-life situations.
"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,” said Professor Daniele Faccio, from Heriot-Watt University.
"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.
Operating in a similar way to sonar, the device scatters laser light and then detects its bounce-back at 20 billion frames a second.
"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,” explained Genevieve Gariepy, a PhD researcher in Heriot-Watt University's extreme light group, "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 for the light return to the camera, the researchers can establish how far the hidden object is.
“By recording the shape of the laser 'echo', we know what direction it's coming from,” Gariepy added. “It takes only a second for the camera to record all of this: so if the object is moving, we can follow it."
The camera works over a distance of several metres and the researchers are currently trying to further enhance the technology to enable 3D reconstruction.
"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,” Faccio said.
The technology could also find applications in situations when rescue teams need to assess whether it's safe to enter a room or building.