Zenghu Chang (University of Central Florida)
Monitoring motion of excited electrons in helium atoms on its natural timescale with attosecond transient absorption.
|Title:||Ultrabroadband Isolated Attosecond X-ray Pulses|
|Affiliation:||Pegasus and Distinguished Professor of Physics and Optics at the University of Central Florida|
Monitoring motion of excited electrons in helium atoms
on its natural timescale with attosecond transient absorption.
|Attosecond science and technology has rapidly grown into one of the most-exciting forefronts in modern physics. Since 2001, significant progress has been made in both attosecond source development and applications. At the present time, the shortest duration of such pulses reaches 67 as. The photon energy of isolated attosecond pulses is below 150 eV. The dominating driving lasers for achieving these performances are the Ti:Sapphire lasers centered at 800 nm. Very recently, we have extended the spectra of isolated attosecond pulses to 450 eV by using long-wavelength driving lasers in combination with polarization gating, which opens the door for monitoring attosecond charge motion by observing core-to valence level transitions.|
|Biographical Sketch:||Zenghu Chang is a Pegasus and Distinguished Professor of Physics and Optics 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 Jiaotong University in 1982. He then earned a doctorate at the Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, in 1988. From 1991 to 1993, Chang visited the Rutherford Appleton Laboratory sponsored by the Royal Society fellowship. He worked at the University of Michigan after 1996. Then joined the physics faculty at Kansas State University in 2001. He moved to the University of Central Florida in Orlando in 2010. His notable contributions include inventing the Double Optical Gating for the generation of broadband single isolated attosecond pulses and for extending the cutoff of high-order harmonics using long wavelength driving lasers. His group generated the shortest laser pulse, 67 as, which is the current world record. He is the author of the book “Fundamentals of Attosecond Optics.”|