In conventional imaging methods, a beam of photons (or other particles) is reflected off the object to be imaged. After the beam travels to a detector, the information gathered there is used to create a photograph or other type of image. In an alternative imaging technique called “ghost imaging,” the process works a little differently: an image is reconstructed from information that is detected from a beam that never actually interacts with the object.
Click here for original story, Quantum ghost imaging improved by using five-atom correlations
Source: Phys.org