Shanghai team in laser breakthrough

Chinese scientists have used a novel approach to achieve free-electron lasing that may result in the production of low-cost, tabletop FEL devices, offering the possibility of breakthroughs in multiple disciplines.

It was the first time researchers had achieved FEL using a laser wakefield electron accelerator, a method for producing high-energy electron beams using an accelerating field structure.

After nearly a decade's effort, a paper about the achievement by the Chinese Academy of Sciences' Shanghai Institute of Optics and Fine Mechanics was published as the cover story of the United Kingdom-based scientific journal Nature, on Thursday.

X-ray FEL can be used to detect the internal dynamic structure of matter and study the interaction of light with atoms, molecules and condensed matter, which may lead to breakthroughs in disciplines as diverse as physics, chemistry, structural biology, medicine, new materials, energy and the environment.

"The features of FEL, including its super-high resolution rates regarding time and space and super-strong peak brightness, make it possible to realize three-dimensional, multimodal imaging of matter with ultrahigh precision," said Wang Wentao, a professor at the institute and a co-first author of the paper.

"The application of the potential technology is likely to greatly expand humanity's understanding of the mysteries of life and the evolution of living things."

Experts said there are eight FEL facilities operating around the world but they range in size from 300 meters to 3.4 kilometers and use radio frequency electron accelerators not suited to the development of small FEL facilities that could be more widely used.

"We proved the feasibility of the new technical route with a laser electron accelerator with ultrahigh acceleration capability, and downsized the facility size from the kilometer level to 12 meters," said Leng Yuxin, deputy director of the institute.

Researchers said small FEL facilities have great potential in producing images of rapidly moving objects. Even if a patient-an uncooperative child, for example-undergoing X-ray imaging was moving quickly, they said, a machine using the technology would still be able to produce impressive high-resolution images.