Researchers at the Massachusetts Institute of Technology managed to get super-clear images of objects in almost 100 percent darkness, thanks to the collection of information from single photons recorded by each individual pixel solid state detector.
A photo from open sources
This achievement can help, for example, in the study of fragile biological materials like the human eye that can be damaged by stronger backlighting. Also this development can find use in military intelligence, allowing you to take notes CCTV with minimal backlight to avoid detection by the adversary.
To get these pictures, an electrical engineer from MIT Ahmer Kirmani and his colleagues have developed an algorithm that takes into account correlations between adjacent parts of the highlighted object, as well as physics of dimly lit measurements.
“We haven’t invented a new laser or a new detector,” notes Kirmani. Instead, his team applied a new an algorithm that can be used with standard and ubiquitous common photon detector.
In this system, the low-energy pulses of the visible laser lights shoot at a given portion of space until at least one photon will not be a recorded detector; each the highlighted dot corresponds to one pixel of the final Images.
Fluctuations in the time it takes photons to reflect from object, provide information about its depth – this is standard a way to recreate three-dimensional structures. However, the algorithm developed by Kirmani, allows to achieve this result, using only one hundredth of the number of photons that are needed existing LIDAR technologies.
Since the laser generates light with only one wavelength, Images are obtained in monochrome. However, the new technique allows to some extent identify the various materials of the object based on the extent to which they reflect the color of the laser.
In his experiment simulating real conditions, the researchers used various noise reduction algorithms, which allowed them to get high resolution 3D pictures, using just one million photons. For comparison, a snapshot same quality made by smartphone camera at office lighting, would require several hundred trillion photons, reports Kirmani.
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