This New Laser Can Expose A Whole Room By Entering Through A Tiny Keyhole

Imagine if you had the superpower to see through walls? Well that’s pretty much impossible right now but researchers at Stanford Computational Imaging Lab have come up with the next best thing using the technique called non-line-of-sight imaging (NLOS).

NLOS is not a new concept at all, rather it has been used in research laboratories for many years not to develop cameras that can see around corners and create images of objects that are not in the camera’s field of view. This technology previously used flat surfaces such as floors or walls that were in the line of sight of both camera and the blocked object. A series of light pulses from the camera bounced off these surfaces and back to the camera and their speed was calculated using different algorithms which was used to determine the shape of the object. But since it wasn’t that accurate, the results were not high-resolution either until now.

The researchers developed the keyhole imaging technique which works by passing a single laser beam through a tiny hole in an enclosed space. The light bounces off the wall, an object in space and then bounces off the wall again, resulting in countless photons reflecting back through the hole into the camera. The camera uses a single photon avalanche photodetector which measures the point in time of their return.

This technique doesn’t work quite well on static objects since it can not calculate what it is seeing but for moving objects coupled with laser pulses, it generates enough useful data over a long exposure time for the algorithm to create an image of what it sees. While the end result is still not of great quality, it has the potential to become a useful asset for the military in raiding suspicious places without having to actually break the door and rush in.