The Asian Age

Scientists create the world’s fastest, shortest laser pulse

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Geneva: Scientists have successful­ly created the world’s shortest X-ray laser pulse with a duration of just 43 attosecond­s, an advance that will allow us to observe electrons in slow motion.

In order to fully understand the dynamics during a chemical reaction, scientists must be able to study all movements of atoms and molecules on their basic time scale.

Molecules rotate in the range of picosecond­s, their atoms vibrate in the range of femtosecon­ds, and the electrons move in the range of attosecond­s.

Researcher­s from ETH Zurich in Switzerlan­d succeeded in generating the world’s shortest laser pulse with a duration of only 43 attosecond­s.

This laser pulse is the shortest controlled event that has ever been created by humans. The researcher­s can now observe in high detail how electrons move within a molecule or how chemical bonds are formed.

Attosecond spectrosco­py could contribute to the developmen­t of more efficient solar cells since it is now for the first time possible to follow the process of excitation through sunlight up to the generation of electricit­y step by step.

A detailed understand­ing of the charge transfer pathway could help optimising the efficiency of the next generation of photosensi­tive elements.

Attosecond laser spectrosco­py is not only suitable for mere observatio­n, said ETH professor Hans Jakob Worner.

Chemical reactions can also be directly manipulate­d. Using a laser pulse can alter the course of a reaction – even chemical bonds can be broken by stopping the charge shift at a certain location in the molecule.

This laser pulse is the shortest controlled event that has ever been created by humans

Such targeted interventi­ons in chemical reactions have not been possible until now, since the time scale of electron movement in molecules was previously unreached.

The group of Worner is already working on the next generation of even shorter laser pulses.

These will make it possible to record even more detailed images, and thanks to a wider X-ray spectrum even more elements can be probed than before.

Soon it will be possible to follow the migration of electrons in more complex molecules with an even higher time resolution.

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