London, June 20 : Experts at the Max Planck Institute for Quantum Optics in Germany have devised a way to generate the shortest-ever flash of light, that is, just 80 attoseconds long (billionths of a billionth of a second).
Eleftherios Goulielmakis, a member of the team behind this work, revealed that the light pulses were produced by firing longer, but still very short, laser pulses into a cloud of neon gas.
He said that that the laser gave a kick of energy to the neon atoms, which then released the energy in the form of brief pulses of extreme ultraviolet light.
According to him, the trigger pulses fired at the neon cloud were themselves only 2.5 femtoseconds (billionths of a millionth of a second) long, and that they contained only one or two oscillations of a light wave so that they packed a compact energy punch when they reached the neon cloud.
For creating such trigger pulses, Goulielmakis and his colleagues had to corral the trigger-pulse photons into a tightly packed bunch using a device called a chirped mirror.
The researchers said that the multi-layered mirrors made the photons at the front of a pulse travel further than the slower photons at the rear did, producing a tight pack of photons that hit the neon atoms at roughly the same time.
With a view to determining how short the light flashes from the neon atoms were, the researchers directed them onto a second neon gas cloud.
Since each flash was intense enough to completely ionise a neon atom and release an electron, Goulielmakis and his colleagues could use those electrons like a flashgun to illuminate some of the original 2.5 femtosecond trigger pulses of laser light.
"Only sampling them with a 'sampler' way shorter than that can render them visible," New Scientist magazine quoted Goulielmakis as saying.
Upon analysing the image of the laser, the researchers came to the conclusion that the flashes of light used to make the electrons lasted just 80 attoseconds, the shortest ever made.
Jonathan Marangos at Imperial College London, UK, says that the super-short flashes may help image the movement of electrons around large atoms.
"Any better understanding of the microscopic world is going to have an impact across all of science," he says.
The previous record for the shortest light pulse was 130 attoseconds, set in 2007.
"To go from 130 to 80 attoseconds is a major step," says Marangos.
In the future, Goulielmakis hopes to produce light pulses of 24 attoseconds, the atomic unit of time, defined as how long it takes an electron to travel from one side of a hydrogen atom to the other.
A research article describing the study has been published in the journal Science.