3-D images, with only one photon per pixel
Lidar rangefinders, which are common tools in surveying and in autonomous-vehicle control, among other applications, gauge depth by emitting short bursts of laser light and measuring the time it takes for reflected photons to arrive back and be detected.In this week’s issue of the journal Science, researchers from MIT’s Research Laboratory of Electronics (RLE) describe a new lidar-like system that can gauge depth when only a single photon is detected from each location. Since a conventional lidar system would require about 100 times as many photons to make depth estimates of similar accuracy under comparable conditions, the new system could yield substantial savings in energy and time — which are at a premium in autonomous vehicles trying to avoid collisions.The system can also use the same reflected photons to produce images of a quality that a conventional imaging system would require 900 times as much light to match — and...