J.R. Macdonald Laboratory News

Lew Cocke

 

The J.R.Macdonald Laboratory has now firmly established AMO (Atomic, Molecular and Optical) ultrafast as its theme.  We continue to work with the Kansas Light Source (KLS) 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.  During the past year, Zenghu Chang’s group has been able to stabilize the phase of the “carrier” of the laser relative to the envelope.  A second technical development has been the addition of a “Dazzler” to the system by Brett DePaola’s group.  This device is capable of generating “designer” pulses by slicing out or modifying user-chosen slices of the wavelength range of the pulse.  The demand for the laser beam is high, and we are working hard to install a second amplifier which will allow us to double the amount of “beamtime” we have available to users.  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 ultrashort pulses of energetic ions through the “Picopulse” project headed by Kevin Carnes.  As I write, the KLS room is being expanded to house our improved laser and the Dazzler, as well as to allow room for the installation of a new laser.

Our three year review was held in November.  This time it brought to our laboratory five highly respected members of the AMO community, as well as our program managers from the Chemical Sciences Division of Basic Energy Sciences in the U.S. Department of Energy.  The scientific evaluation of the program was very positive.

We have had many changes in personnel in the laboratory.  As postdoc, Jarlath McKenna from Queen’s University in Belfast has joined Itzik’s group in November, replacing Pengqian Wang who left to take an Assistant Professor position at Western Illinois University.  Hiroki Mashiko, from Katsumi Midorikawa’s group at RIKEN, Japan, has joined Zenghu Chang’s group for three years, and Ximao Feng, a new Ph.D. from Western Michigan University, has joined this group as a postdoc.  In Chii Dong Lin’s group, John RuiHua Xie and Zhangjin Chen have both joined as new postdocs.  A.T. Le has been promoted to Assistant Research Professor.  Toru Morishita and Hoang Le are visitors for extended periods, while K.Toyota, H.Matsunaga, T.F. Jiang, Y.M. Lee and A. Igarashi were shorter term visitors.  Marlene Wickenhauser returned to Vienna Institute of Technology in January 2006 after one year in that group and has earned her Ph.D. degree there.  Georgi (“Goga”) Veshapidze joined Brett DePaola’s group last winter as a postdoc, and Brett’s student, Mudessar Shah, completed his Ph.D. defense and has taken a postdoctoral position with Georg Raithel at the University of Michigan. Vladimir Roudnev, a postdoc with Brett Esry, left in June to take a postdoc position at the University of Kentucky.  New graduate students (advisor) in the JRM laboratory include Maia Magrakvelidze (Litvinyuk), Hyounguk Jang (DePaola), Nora Johnson (Ben Itzhak), Cheng Jin and Junliang Xu (Lin). Sam Fahrenholtz has joined the group of Ben Itzhak as an undergraduate research assistant.

The labs of Kristan Corwin and Brian Washburn have had a productive year.  This year, Brian has converted his empty lab into an ultrafast nonlinear fiber optics laboratory, together with graduate student Jinkang Lim and undergraduate Daniel Nickel.  They have constructed and numerically modeled an ultrashort pulsed fiber laser, which they will use for optical frequency combs and potentially for quantum communications.  Next door, Kristan’s group now includes postdoc Karl Tillman, grad students Rajesh Thapa, Kevin Knabe and Andrew Jones, and undergraduates Aaron Pung and Asma Al-Rawi. Together with Brian, they have created a stable frequency comb from an ultrafast Chromium forsterite laser.  Also, they have filed a provisional patent on a new “reflected pump” technique for measuring the spectra of molecules inside novel hollow optical fibers and improved techniques for splicing these fragile hollow fibers to standard optical fibers.  They are now poised to combine these techniques to develop a portable optical frequency standard, which are of essential interest to the telecommunications industry.

We have had a long parade of excellent colloquium speakers in AMO this fall semester. These include Gerhard Paulus from Texas A&M, Jianping Zhou from Spectra Physics, Haruka Maeda from the University of Virginia, Bruce Shore (a returning son) from Lawrence Livermore National Laboratory, Chris Greene from the University of Colorado and Chris Monroe from the University of Michigan.  Outside speakers at our AMO seminar this semester have included Richard Brédy from CRNS, France, Tom Kirchner from University of Clausthal, Germany, Marcus Schöffler and Mathias Smolarski from the University of Frankfurt, Germany, Shin Watanabe from UEC, Japan, Bruce Shore from LLNL, and Jarlath McKenna, Belfast, Ireland.