Fastest X-Ray Flashes Produced

View in the lab of Zenghu Chang with the experiment to produce the shortest x-ray flashes ever. (Source: UCF)

A research team at the Uni­versity of Central Florida has demons­trated the fastest light pulse ever developed, a 53-atto­second X-ray flash. The group led by Zenghu Chang beat its own record set in 2012: a 67-atto­second extreme ultra­violet light pulse that was the fastest at the time. In 53 atto­seconds, light travels less than one-thousandth of the diameter of a human hair.

In the same way high-speed cameras can record slow-motion video of flying bullets, atto­second light pulses allow scientists to capture images of fast-moving electrons in atoms and molecules with unpre­cedented sharpness. The pulses Chang has now demons­trated are not just shorter in duration, but also in wave­length. The new light reaches an impor­tant spectral region of the “water window,” where carbon atoms absorb strongly but water does not.

“Such atto­second soft X-rays could be used to shoot slow-motion video of electrons and atoms of biolo­gical molecules in living cells to, for instance, improve the effi­ciency of solar panels by better under­standing how photo­synthesis works,” said Chang, a UCF Trustee Chair Professor in CREOL, The College of Optics & Photonics, and the Depart­ment of Physics. Chang is the director of the Insti­tute for the Frontiers of Attosecond Science and Tech­nology (iFAST), located in the Physics Depart­ment, where the experi­ments were carried out.

X-rays interact with the tightly bound electrons in matter and may reveal which electrons move in which atoms, providing another way to study fast processes in materials with chemical element speci­ficity. That capability is inva­luable for the develop­ment of next-gene­ration logic and memory chips for mobile phones and computers that are a thousand times faster than those in use today. Producing atto­second X-rays requires a new type of high power driver: femto­second lasers with a long wavelength. It’s an approach that Chang and his team have pioneered. (Source: UCF)

Reference: J. Li et al.: 53-attosecond X-ray pulses reach the carbon K-edge, Nat. Commun. 8, 186 (2017); DOI: 10.1038/s41467-017-00321-0

Link: Inst. for the Frontier of Attosecond Science and Technology, CREOL, University of Central Florida, Orlando, USA

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