In the system, a laser pulse that lasts less than one trillionth of a second is used as a flash to illuminate a scene. The light returning from the scene is then collected by a camera at a rate equivalent to roughly half a trillion frames per second.
When a light pulse enters the camera through a narrow slit along one direction, it is deflected in the perpendicular direction so that the first photons that arrive hit the detector in the camera at a different position compared to photons that arrive later.
The image produced by the camera is two-dimensional, but only one of the dimensions -- the one corresponding to the direction of the slit -- is spatial. The other dimension, corresponding to the degree of deflection, is time.
To produce 2-D videos of a scene, the researchers must perform the same experiment -- such as passing a light pulse through a bottle -- over and over, continually repositioning the camera over a period of an hour to gradually build up a 2-D image.
After an hour, the researchers accumulate hundreds of thousands of data sets, each of which plots the one-dimensional positions of photons against their times of arrival. The raw data is then mathematically reconstructed into a set of sequential 2-D images.
The researchers believe that the camera could have a variety of applications in industrial imaging where it could be used to analyze faults and material properties, as well as scientific imaging for understanding ultrafast processes.
More information on the camera can be found here.
-- By Dave Wilson, Senior Editor, Vision Systems Design