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. The recognition of JRML research in this field helped our bid to host the attosecond physics meeting in the summer of 2009. This meeting will be co-chaired by Chii-Dong Lin and Zenghu Chang. 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. A “Dazzler”, a device capable of generating “designer” pulses by slicing out or modifying user-chosen slices of the wavelength range of the pulse, was added to the system and shortly  afterwords Brett DePaola’s group produced exciting results with it. The demand for the laser beam is high, and Zenghu Chang’s group has been working hard to install a second amplifier, which will allow us to double the amount of beamtime we have available to users in the coming year.

Projects which involve both the laser beam and the ion beams from the accelerators include the disintegration of molecular ions from the ECR source by Itzik Ben-Itzhak’s group and the generation of picosecond pulses of energetic ions from the Tandem accelerator by Kevin Carnes and coworkers. As I write, a new laser funded by a MURI grant is being installed in the expanded KLS room. This ~1M$ per year (for the next three years) grant supports collaborative research at JRML, Texas A&M and NRC Canada. This effort lead by Zenghu Chang will have clear benefits for the lab and gives JRML a jump start to become a leading lab in ultrafast science. We were excited to see three publications of Lew Cocke’s collaborative research on the interaction of light with simple molecules in the prestigious Science magazine (Vol. 315. p. 629; Vol. 317. p. 1374; and Vol. 318. p. 949).

The physics department hired a new faculty member, Vinod Kumarappan, who joined our group this fall. Vinod completed his PhD at the Tata Institute for Fundamental Research in Mumbai, India, where he was a student of Deepak Mathur. He followed that with post-doctoral stints at the Univ. of Maryland at College Park and at the Univ. of Aarhus, Denmark. Vinod is setting up a new lab and plans to use the KLS to align gas-phase molecules and to study their properties and dynamics on ultrashort timescales.

We have had many additional changes in lab personnel. As new postdocs, Sankar De, from the Inter-Univ. Accelerator Centre in New Delhi, India has recently joined Igor Litvinyuk’s group, and Shouyuan Chen from the University of Nebraska will join Zenghu Chang’s group soon. Samuel Michau from the Univ. of Bordeaux, France, has joined Chii-Dong Lin’s group. Four of our graduate students (advisor) received their PhD’s and moved to postdoc positions: Shambhu Ghimire (Chang) now at the Univ. of Michigan, Mahendra Shakya (Chang) now at the Univ. of New Mexico, Chakra Maharjan (Cocke) now at the Univ. of Nebraska, and Thomas Niederhausen (Thumm) now at the Univ. of Madrid, Spain. New graduate students (advisor) in the JRML include Ben Gramkow and Wei Cao (Cocke), and Mike Chini and Shuai Hu (Chang). Finally, Lew Cocke recently stepped down from being the JRML director after several years of good leadership, and Itzik Ben-Itzhak has taken this challenging role upon himself.

The groups of Kristan Corwin and Brian Washburn have made significant contributions in nonlinear optics and precision metrology.  Progress in Kristan’s lab has been made towards the stabilization of a Chromium:forsterite laser frequency comb where postdoc Karl Tillman and graduate student Rajesh Thapa have revealed the comb’s noise dynamics.  Graduate students Kevin Knabe and Andrew Jones have demonstrated saturation spectroscopy in a hollow core “kagome” fiber.  The fiber comes to us from the group of Fetah Benabid, University of Bath, where Kevin will visit in the spring semester.  Undergraduate Aaron Pung has developed laser fusion splices in a vacuum chamber.  Brian, graduate student JinKang Lim, and undergraduate Daniel Nickel have made significant progress towards the stabilization of an all-fiber based frequency comb and have demonstrated pulse compression in a hollow core fiber.  Visiting Professor Yishan Wang has joined Brian’s group to develop a high repetition rate fiber laser.  Collaborations between these groups will develop a portable optical frequency standard.

We have had a long parade of excellent colloquium speakers in AMO this year. These include Vinod Kumarappan from the Univ. of Aarhus, Denmark, Francis Robicheaux from Auburn Univ., David Villeneuve from the National Research Council, Canada, and finally the NEFF LECTURE IN PHYSICS speaker Rick Trebino from the Georgia Institute of Technology.  Outside speakers at our AMO seminar this year have included Andre Staudte from the National Research Council, Canada, Toru Morishita from UEC, Tokyo, Japan, (our former student)  Jesus Hernandez from Auburn Univ., Jacob Roberts from Colorado State Univ., Rick Trebino from the Georgia Institute of Technology, Jorge Rocca from Colorado State Univ., Samuel Bohman from RIKEN, Japan, Jean-Claude Diels and Ladan Arissian from the Univ. of New Mexico, Masayuki Katsuragawa from UEC, Tokyo, Japan,  Shouyuan Chen from the Univ. of Nebraska,  Matthias Kling from the Max Planck Institute for Quantum Optics, Germany, and David Villeneuve from the National Research Council, Canada.