Accelerating a free electron with a laser has been a longtime goal of solid-state physicists. David Cline, a distinguished professor in the UCLA Department of Physics and Astronomy, and Xiaoping Ding, an assistant researcher at UCLA, have conducted research at Brookhaven National Laboratory in New York and have established that an electron beam can be accelerated by a laser in free space.
This has never been done before at high energies and represents a significant breakthrough, Cline said, adding that it also may have implications for fusion as a new energy source.
In free space, a plane-wave laser is unable to accelerate an electron, according to the Lawson-Woodward theorem, posited in 1979. However, Yu-kun Ho, a professor at China's Fudan University in Shanghai, and his research group have proposed a concept of what physicists refer to as the capture-acceleration scenario to show that an electron can be accelerated by a tightly focused laser in a vacuum.