USING a cameraphone to catch the indivisible packets of light energy known as photons is easy: around a trillion of them impinge on its sensor every second. Catching just one photon, however—and knowing exactly when it arrived—is far trickier. Many branches of research in the physical sciences depend on specialised kit that can do this, but quotidian equipment is not up to the job. “So what?” you might think. But there is at least one application outside the laboratory that it might be useful for. This is seeing what is around a corner, something both soldiers and drivers would like to be able to do. And, as they describe in Nature Photonics, a group of researchers led by Daniele Faccio of Heriot-Watt University, in Edinburgh, have indeed worked out a way to capture simple movies of what is around the bend.
Dr Faccio’s group is one of several trying to do this. All use a method similar to that employed in radar, except that it substitutes light for radio waves and is thus known as LIDAR. Unlike conventional LIDAR, though, the pulses sent out from looking-around-the-corner equipment have to bounce off three things before they make it back to the detector. First, they must be reflected from something in the line of sight of their source. This pushes some of them in the direction of the hidden target. Then, they have to be reflected from...Continue reading
Source: Science and technology http://ift.tt/1Qhh6W3
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