UCF researchers create new ultrafast light source for attosecond physics

May 13, 2014
Zenghu Chang, a researcher at the University of Central Florida (UCF; Orlando, FL), and his international team have developed a new ultrafast light source for observing electron motion in molecules at the point before the nuclei start to move.

Zenghu Chang, a researcher at the University of Central Florida (UCF; Orlando, FL), and his international team have developed a new ultrafast light source for observing electron motion in molecules at the point before the nuclei start to move; the technique can potentially lead to the generation of high-order harmonics and attosecond pulses at repetition rates of greater than 1 MHz.1

To do this, Chang and his team borrowed an idea from Chang's earlier work in the area of ultrafast lasers, in which 67-attosecond pulses of extreme ultraviolet light were created.

"The charge migration that theorists have been predicting since 1999 happens so quickly we haven't been able to observe it yet," Chang says. "It's very exciting, because we have found a new way to build light sources that may allow us to see it in the future."

Being able to see this superfast interaction between electrons will help scientists understand the rules that govern the quantum-mechanics world. By being able to observe what actually happens, scientists can also begin to understand interactions that help improve the efficiency of solar cells.

"We control the below-threshold harmonic light emission by using electromagnetic fields with time-dependent ellipticity, like we have done to the above-threshold high-order harmonics," says Chang. "We thought: Could we use the same gating fields to show the dependence of the below-threshold harmonic intensity on the carrier-envelope phase of the driving laser? It took us some time to find the right experimental parameters, but the answer is yes."

The team includes researchers from the Center for Quantum Science and Engineering and the Department of Physics at the National Taiwan University, the Materials Sciences Division at Lawrence Berkeley National Laboratory (Berkeley, CA), and the Department of Physics at St. Petersburg State University in Russia.

The Defense Advanced Research Projects Agency (DARPA), National Science Foundation (NSF), U.S. Department of Energy (DOE), National Science Council of Taiwan, and National Taiwan University funded the research.

REFERENCE:

1. Michael Chini et al., Nature Photonics (2014); doi:10.1038/nphoton.2014.83

About the Author

John Wallace | Senior Technical Editor (1998-2022)

John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.

Sponsored Recommendations

Download New Product Development Strategies White Paper

March 27, 2025
Discover the importance of new product innovation, different process methods, and best practices for optimizing your company’s strengths.

Manufacturing Considerations for Tolerancing Aspheres

March 13, 2025
Understand the critical factors in manufacturing aspheres and how Lacroix Optics ensures precise tolerancing in every optical component.

Explore Our Videos: Insights into Precision Optics

March 13, 2025
Get an inside look at Lacroix Optics with our collection of informative videos showcasing our capabilities, innovations, and processes.

Optical Assemblies: Reliable and Precise Solutions

March 13, 2025
Ensure your optical system works seamlessly with Lacroix Optics' custom optical assemblies. Discover the precision and reliability we bring to every project.

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!