First 3D Ghost Images From A Single Pixel
From the MIT Technology Review:
Chinese physicists use ghost imaging technique to make 3D images with a single pixel
Ghost imaging is the extraordinary technique of bouncing a laser beam off an object and making high quality images from the reflected light using a single pixel. This single pixel records many data points which must be stitched together to create the image.
But there is no scanning involved (which would be equivalent to taking an ordinary picture very slowly).
Instead, the data from the single pixel is compared against the intensity of the original laser beam, which must be randomized by passing it through frosted glass. Then any correlations between the original and reflected beam reveal information about the object in the image.
It is these correlations that physicists use to assemble the picture, known as a ghost image.