While a standard camera takes flat, 2-D pictures physicists from Heriot-Watt University obtain 3-D information, such as the distance to a far-away object, by bouncing a laser beam off the object and measuring how long it takes the light to travel back to a detector. The technique is called time-of-flight (ToF), and is already used in automative vehicle vision navigation systems and other applications.

The new system works by sweeping a low-power infrared laser beam rapidly over an object. It then records, pixel-by-pixel, the round-trip flight time of the photons in the beam as they bounce off the object and arrive back at the source. The system can resolve depth on the millimetre scale over long distances using a detector that can ‘count’ individual photons. Lots of applications are planned for the technology.

Pictured below: 3-D images of two of the Optics Express authors, taken in daylight from 910m away. Each standard photograph shows a close-up view of what the scanner sees. The middle left panels show 3-D images with slightly more depth detail that the right-hand panels; this is because the detector spent more time collecting the returning photons for the images on the left than on the right. Credit: Optics Express.

http://www.hw.ac.uk/news-events/news/new-camera-system-creates-high-resolution-3-d-11809.htm