Camera that can see around corners

Scientists will be exhibiting a camera that could eventually peer around corners to see objects that would otherwise be hidden from view at this year’s Royal Society Summer Science Exhibition.

The team from Heriot-Watt University will be demonstrating a new camera which can film at the speed of light allowing them to video pulses of light as they travel through air.

The Creative Cameras exhibit will also be presenting a camera that is able to capture images using only one pixel – work currently being done by researchers from Glasgow University. This approach to imaging allows them to see the world in colours that human eyes and normal cameras cannot see. The technology could have important applications for imaging leaking gases, seeing through smoke and even night vision.

Heriot-Watt’s unique camera has two very special properties. The first is its sensitivity to single photons – each pixel is around ten times more sensitive than a human eye; the second is its speed – each pixel can be activated for just 67 picoseconds, that’s more than a billion times faster than a person can blink.

Dr Jonathan Leach of Heriot-Watt University says:

“Observing light in motion requires ultrafast recording technology. Though such technologies have been successfully developed in the past, they all require light propagation through a scattering object or medium e.g. milky water, in order to provide sufficient signal for a measurement. Our camera is different and is sensitive and fast enough to directly record light moving in free space.

The camera lends itself to applications where precise timing information is needed and one such application is recording the scattered light from objects hidden from view, enabling us to look around corners. The technology could be used in many ways, ranging from search and rescue missions where faint signals will allow trapped people to be found to medical imaging inside the body where new forms of endoscopy are enabled by time-of-flight imaging.”

Most cameras contain millions of light-sensitive detectors, called pixels, which are used to capture images. Dr Matthew Edgar and colleagues from Glasgow University have built a camera that has only one pixel.

Millions of tiny mirrors are used to reflect the light from a scene as a series of patterns onto a single pixel. The pixel can be made sensitive to nearly any colour, and a computer algorithm uses the reflected light and the mirror patterns to produce images.

Dr Edgar says of the camera he is working on:

“Normal cameras work well with visible light but getting images in ultraviolet or infrared can be hard. Our single-pixel detector can easily be made to capture information far beyond the visible, reaching wavelengths from X-ray to terahertz. This means it could be used to look for the telltale gases which leak from the ground where oil can be found, for example, or it could be tuned into the terahertz range to probe just below the skin to search for tumours or other medical conditions.”

The team from Glasgow University will also be demonstrating a simple camera attachment that allows them to capture 3D pictures using only one camera from one perspective: a technique fundamentally different to conventional 3D imaging approaches which require two or more cameras.

Visitors to the exhibit will be able to have their photo taken in a 3D photobooth, see through a wall with the single-pixel camera and image light traveling in air.