Atomic Physics Research News

Itzik Ben-Itzhak

The J.R. Macdonald Laboratory has now firmly established AMO (Atomic, Molecular and Optical) ultrafast laser physics as its research theme. Four of our faculty, Lew Cocke, Zenghu Chang, Uwe Thumm and Itzik Ben-Itzhak, were invited to present their research in the central ICOMP-08 conference held in Heidelberg, Germany. Also, we were selected to host the attosecond physics international conference in July 2009. Chii-Dong Lin and Zenghu Chang, the co-chairs, are leading our efforts to organize this meeting. Our work also received some attention by the media (see http://www.kstate.edu/media/newsreleases/oct08/laserlab102808.html).

The Kansas Light Source (KLS) continues to serve as our main workhorse, now scheduled essentially 24 hours per day 7 days per week. This laser delivers 25 fs, 800 nm pulses with 3 mJ of energy at one kilohertz. The pulse can be shortened to 6 fs and the phase of the “carrier” of the laser relative to the envelope can be stabilized. Zenghu Chang’s group has been working hard to keep up with the high demand for laser time, while continuously developing new capabilities such as 140 attosecond laser pulses. A “Dazzler”, a device capable of generating “designer” pulses by slicing out or modifying user-chosen slices of the wavelength range of the pulse, has been used by Brett DePaola’s group and by Eric Wells, from Augustana College, to control reaction dynamics of atoms and molecules. We were excited to see Lew Cocke’s collaborative research on the interaction of light with simple molecules in the prestigious Science magazine (Vol. 320.p.920 and Vol. 322.p.1081). Lew’s group is conducting similar cutting-edge experiments in our laboratory, in which a train of attosecond pulses is generated and used to probe atoms and molecules. Igor Litvinyuk’s group used intense laser pulses for time-resolved imaging of molecules – Coulomb explosion imaging with COLTRIMS and angle-resolved photo-electron spectra with their new velocity map imaging setup. Vinod Kumarappan has completed the development of his new lab space for molecular alignment and orientation studies. In collaboration with Steve Lundeen from Colorado State Univ. we installed a new permanent-magnet ECR ion source, which has been used already by Itzik Ben-Itzhak’s group in crossed-beam studies of molecular ions and intense laser beams.

The JRML theory effort paralleled our experimental work. For example, Chii-Dong Lin’s group focused on retrieval of target structure information from laser-induced measured rescattered electron momentum distributions, Uwe Thumm’s group focused on time-series analysis of vibrational nuclear wave-packet dynamics in D₂⁺, and Brett Esry’s group focused on a general theory of carrier-envelope phase effects.

After many years in leadership, Distinguished Professor Pat Richard retired and moved with Dea to Florida. Horst Schmidt-Böcking from the Univ. of Frankfurt, Germany, the Davisson-Germer Prize Recipient 2008, was the keynote speaker at Pat’s farewell party, which brought back to K-State many of Pat’s former collaborators.  We have had many additional changes in lab personnel. As new postdocs, Jesus Hernandez, a former K-State undergraduate student, has joined Brett Esry’s group after receiving his PhD from Auburn University, Chenghua Zhang from Purdue University has joined Uwe Thumm’s group, Feng He and Kamal Singh from the Max Planck Institute for Complex Systems, Dresden, Germany, have joined Uwe Thumm’s and Lew Cocke’s groups, respectively, and Kun Zhao from the University of Nebraska-Lincoln will join Zenghu Chang’s group soon.  A couple of our postdocs moved to new jobs: Chengquan Li now at Coherent Inc., and Goga Veshapidze now at the Institute for Molecular Science in Okazaki, Japan. Five of our graduate students (advisor) received their PhD’s and moved to postdoc or industry positions: Eric Moon (Chang) now at Quantronix Corp., Rajesh Thapa (Corwin) now at IMRA America, Marc Trachy (DePaola) now at Lockheed Martin, Max Sayler (Ben-Itzhak) now at Jena University, Germany, and Predrag Ranitovic who recently received his PhD from Stockholm University on research he conducted at JRML under Lew Cocke's guidance is still at K-state.  New graduate students (advisor) in the JRML include: Michael Chini (Chang), Rajesh Kadel (Washburn), Xiao-Ming Ren (Kumarappan), and Mohammad Zohrabi (Ben-Itzhak).

The groups of Kristan Corwin and Brian Washburn specialize in nonlinear optics and photonic crystal fibers, and their use for infrared frequency metrology.  We have stabilized, for the first time, a fiber laser based on carbon nanotubes which provide the saturable absorber.  This frequency comb has been used to characterize an acetylene filled fiber reference. In addition, we further developed the Chromium:forsterite laser comb and improved the sealing of gas in photonic crystal fibers.  We have two new Department of Defense funded projects: one to create a molecular gas-filled hollow optical fiber laser, and the second, jointly with Precision Photonics and the University of New Mexico, to develop and commercialize gas filled fiber lasers. 

We have had a long parade of excellent colloquium speakers in AMO this year. Leading this group was Nobel Laureate William D. Phillips from NIST/Univ. of Maryland who also presented the PETERSON PUBLIC LECTURE. Thomas Pfeifer from UC-Berkeley, Hiromichi Niikura from the National Research Council, Canada, Mette Gaarde from the Louisiana State Univ., Eleftherios Goulielmakis from the Max Planck Institute for Quantum Optics, Germany, Katsumi Midorikawa  from RIKEN, Japan, Min Xiao from the Univ. of Arkansas, Barry Dunning from Rice Univ., Horst Schmidt-Böcking from the Univ. of Frankfurt, Germany, Donald Umstadter from the Univ. of Nebraska-Lincoln, and the NEFF LECTURE IN PHYSICS speaker Philip Bucksbaum from Stanford University.  Outside speakers at our AMO seminar this year have included Danielle Braje from NIST, Alan Fry from Coherent Company, Barry Dunning from Rice Univ., Kun Zhao from the Univ. of Nebraska-Lincoln, Chang Hee Nam from KAIST, Korea, Akira Suda from RIKEN, Japan, Jeff Nicholson from OFS Labs, Matt Bohn from the Air Force Institute of Technology, and Robert Lucchese from Texas A&M Univ.