Harmonic Generation Promising for Powerful Light Source

A new approach to harmonic generation aims to create smaller, more powerful tabletop light sources for laboratory research, particularly in the emerging area of strong-field physics.

“High-order harmonic generation has been considered a very promising way to provide the tabletop coherent light sources in the extreme UV to x-ray regions, but so far is limited by its low intensity,” said Cheng Jin, a lead researcher and physics research associate at Kansas State University.

Light research chart used by Kansas State physicists. Courtesy of Kansas State University.

Jin, university physics professor Chii-Dong Lin and other collaborators proposed a method of synthesizing two- or three-color laser fields in a gas medium to optimize a laser’s waveform and harmonic intensity. They found that it enhanced harmonics by one or two orders of magnitude when combined with high-intensity, high-repetition megahertz lasers.

“With the emerging intense high-repetition megahertz lasers, this paves a way to make high-order harmonic generation as a useful light in the coming years,” Jin said.

The team is building a theoretical framework for the area of strong-field physics, which explores the interaction of matter with laser fields.

“The ultimate goal of this research is to design any waveforms to control physical processes for different applications,” Jin said. “We expect waveform control of intense laser pulses will lead the next wave of research in strong-field physics, and the theoretical study carried out in this work is essential for this research to move forward.”

The research was published in Nature Communications (doi: 10.1038/ncomms5003).

For more information, visit www.k-state.edu.