Example of a three-dimensional profile of an Edinburgh building at a range of 3km

If we direct a pulsed laser towards an object, it is possible to measure the return time-of-flight of the pulse in order to ascertain the distance to the object. By scanning the beam across the field of view, we can reconstruct a full depth profile of the object. Prof. Buller at IPaQS, working with industrial collaborators at Leonardo in Edinburgh, have used time-resolved single-photon measurements to reconstruct three-dimensional images of very distant objects In this work, the team examined a number of sites around the city of Edinburgh at distances up to 10km, using only eye-safe pulsed lasers emitting an average power of only 10mW. Images were reconstructed at an average of less than one photon per pixel by using bespoke computational imaging algorithms.

Optics Express 25, 6450