Prof. Zenghu Chang
University of Central Florida, USA
Title: Novel high power infrared lasers for attosecond science
Abstract:
The advent of Ti:Sapphire lasers in
the 1990s leads to the first demonstration for attosecond XUV pulses in
2001. In recent years, carrier-envelope
phase stabilized lasers at 1.6 to 2.1 micron based on Optical Parametric
Chirped Pulse Amplification pushed attosecond light sources to the “water
window” X-rays, which enabled real-time observation of electron and nuclear
motion in molecules containing carbon, nitrogen and oxygen. A more efficient way of producing long-wavelength, high
energy, femtosecond pulses is through Chirped Pulse Amplification. Very
recently, we have demonstrated the generation of 2.3 mJ, 88 fs, 2.5 µm laser
pulses from a Chirped Pulse Amplifier employing Cr2+:ZnSe crystals
as the active gain media. Our results show the highest peak power at 2.5 µm
with a 1 kHz repetition rate. Such lasers will be powerful sources for studying
strong field physics and extending high harmonic generation towards the keV
X-ray region.
Biography:
Zenghu Chang is a University Trustee
Chair, Pegasus and Distinguished Professor at the University of Central
Florida, where he directs the Institute for the Frontier of Attosecond Science
and Technology. He is a fellow of the American Physical Society and Optical
Society of America. Chang graduated from Xi’an Jiao-tong University in 1982. He
then earned a doctorate at the Xi’an Institute of Optics and Precision
Mechanics, Chinese Academy of Sciences, in 1988. He joined the physics faculty
at Kansas State University in 2001, and moved to the University of Central
Florida in Orlando in 2010. His notable contributions include the demonstration
of high-order harmonic cutoff extension using long wavelength driving lasers in
2001. His group generated the 53-as X-ray pulses reaching the carbon K-edge. He
is the author of the book “Fundamentals of Attosecond Optics.”