If you thought low-light photography was coming on in leaps and bounds, you ain’t seen nothin’ yet. This new camera, developed by researchers at MIT, can capture ultra-sharp images of objects even when they’re illuminated by just a handful of photons.
The technology uses incredibly low-intensity pulses of visible laser light to scan an object of interest. The laser sends pulses towards a specific location until a single reflected photon is recorded by a super-sensitive solid-state detector. Then, the laser is moved and the process repeated. Each illuminated location renders a pixel in the final image.
Then, the variation in the time it takes for the laser pulse to be reflected back to the sensor provides depth information. This might all sound similar to existing light detection and ranging (LIDAR) techniques — because it is! — but the MIT team can do it with one-hundredth the number of photons; in other words, the room can remain practically pitch black. The research is described in Science.
Sadly, the technique uses a single frequency of light, which means that the resulting images are monochromatic, but that’s a minor quibble given the resolution they can obtain in such low-light conditions. The team expect the device will be used to image materials which are easily damaged by high levels of illumination-particularly biological structures like, um, eyes.
But, perhaps more exciting, it opens up the possibilities of cameras that can obtain visible spectrum images while avoiding detection. And who doesn’t want a stealth cam? [Science via Nature]