Dr. D's Research

My research lies in the area of experimental atomic physics. Specifically, I have been active in high-resolution laser spectroscopy, laser cooling and trapping, and light-matter interactions. I am also interested in scientific instrument development. I have also been active in developing methods to expose students to issues relating to scientific professionalism and ethics.

Prior to joining the faculty at Sac State, I worked for two years as a National Research Council Postdoctoral Fellow in the Atomic Spectroscopy Group at the National Institute of Standards and Technology (NIST), in Gaithersburg, Maryland.  While at NIST, I performed high-resolution measurements of the structure of atomic lithium.  These measurements are currently used as benchmarks for testing atomic theory calculations for simple atomic systems.  I was also involved in the development of easy-to-use yet highly accurate wavelength standards for laser spectroscopy.  My collaboration with Dr. Craig Sansonetti in the atomic spectroscopy group continues, where I was a guest researcher in January 2003 and July-August 2003.  During the summer of 2003, Sac State student (and now faculty member) Eliza Morris spent the summer working with Dr. Sansonetti and me as a NIST Summer Undergraduate Research Fellow.

I have also received a grant from the National Science Foundation with Dr. Roy Dixon from the Chemistry Department to develop and test a new detector for a high-performance liquid chromatography (HPLC) system. This system is less costly than many detectors currently on the market. Our system is currently deployed at Sacramento State and is being used by a number of faculty members in the Biological Sciences and Chemistry Departments.

In the Spring of 2011, I was on sabbatical and performed research with Prof. Christopher Cappa at UC Davis in the Department of Environmental Engineering. We moderninized a cavity-ring down spectroscopy system that is used to measure airborne aerosol concentrations. Sac State student Sage Bauers contributed significantly to this work. 

As a graduate student at the University of Maryland, I studied the dynamics of atomic collisions in the presence of near-resonant radiation (i.e. light at wavelengths near atomic transitions).   We were interested in studying orientational effects on the collisions and developed the "brightest" atom beam to date using laser cooling and trapping forces.  This beam dramatically improved our ability to see collisions because of the high beam density and allowed us to study photoassociation, the optical suppression of photoassociation, and collisional losses between pairs of sodium atoms.  This research provided very fundamental data that is helping us understand how collisions are influenced by the presence of light.

In addition to my atomic physics research, I have been active in technical illustrations.  The first textbook that I illustrated, "Light-Matter Interaction, Volume 1: Fundamentals and Applications" by J. Weiner and P.-T. Ho, was published in 2003 by Wiley-Interscience and is available from all the traditional textbook vendors. I partially illustrated the second volume of this series, "Light-Matter Interaction: Atoms and Molecules in External Fields and Nonlinear Optics", by W. T. Hill III and C. H. Lee. I am happy to review proposals for other books. 

Papers

My Dissertation