Using lasers, cameras can now observe moving objects located around corners, a technology which may one day help vehicles avoid collisions, scientists say.
Previous research found that by firing light pulses at surfaces located in close proximity to an object, the lasers could track items hidden around corners. Because the surfaces act like mirrors, they can scatter the light onto any given target. Scientists can then recreate the shapes of the objects by looking at the light that in reflected off the objects back to the device.
Daniele Faccio, senior author of the study and a physicist at Heriot-Watt University in Edinburgh, Scotland, said that the ability to see behind a wall is quite impressive. According to Faccio, one application of this technology would be a system that helps vehicles see around bends. When the car would sense something coming its way, the system would make the car slow down to avoid collision.
The researchers also made it possible for the camera to observe moving objects concealed behind corners in just a few second, rather than hours (as it happened in a previous research).
The new system consists of a camera and a laser. Researchers say that the laser is able to fire sixty-seven million pulses per second. Each pulse lasts about ten femtoseconds, with one femtosecond being equal to one quadrillionth, or one millionth of one billionth, of a second. The camera can capture photons (packets of light) every fifty picoseconds (one picoseconds equals one trillionth, or one millionth of one millionth of a second).
During the experiment, when the researches fired laser pulses onto a white cardboard that was placed in front of another black cardboard corner, the light reflected onto a hidden item – a human foam statue that was 11.8 inches (30 centimetres) tall.
Only three seconds after it captured the data, the camera was able to locate the object with a precision of 0.4 inches (one centimetre), according to the researchers.
Currently, the system cannot generate 3D images, but Faccio says that future research may help upgrade it so that it can see in full 3D.
The research was published December 7 in the journal Nature Photonics.