By Jason Palmer
Science and technology reporter, BBC News
The fastest imaging system ever devised has been demonstrated by researchers reporting in the journal Nature.
Their camera's "shutter speed" is just a half a billionth of a second, and it can capture over six million images in a second continuously.
Its "flashbulb" is a fast laser pulse dispersed in space and then stretched in time and detected electronically.
The approach will be instrumental in imaging fast-moving or random events, such as communication between neurons.
What is more, the camera works with just one detector, rather than the millions in a typical digital camera.
Gathering steam
Dubbed Serial Time-Encoded Amplified imaging, or Steam, the technique depends on carefully manipulating so-called "supercontinuum" laser pulses.
These pulses, less than a millionth of a millionth of a second long, contain an enormously broad range of colours.
Two optical elements spread the pinprick laser pulses into an ordered two-dimensional array of colours.
It is this "2-D rainbow" that illuminates a sample. Part of the rainbow is reflected by the sample - depending on light and dark areas of the illuminated spot - and the reflections travel back along their initial path.
Because the spreading of the pulse's various colours is so regular and ordered, the range of colours reflected contains detailed spatial information about the sample.
"Bright spots reflect their assigned wavelength but dark ones don't," explained Bahram Jalali, the University of California, Los Angeles professor who led the research.
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