Physical Sciences Division
Pacific Northwest National Laboratory
PO Box 999
Richland, WA 99352
My research is centered on laser-excitation of solids and surfaces. We have ongoing research programs in laser desorption from wide-band gap materials, metal oxides, and semiconductors. Many of the key photophysical processes in laser solid interactions, such as electron/hole-pair generation and recombination, exciton relaxation, and electron-phonon interactions, occur on an ultrafast time-scale. Therefore, we have developed femtosecond laser techniques, in addition to nanosecond studies, to clarify the role of ultrafast phenomena involved in laser material interactions and excited-state condensed-phase processes. Recently, we initiated a program to explore dynamics of mesoscopic surface structures. In particular, we are studying localized and propagating surface plasmons using photoemission electron microscopy and both surface and tip enhanced Raman spectroscopy (SERS and TERS). My team and I are actively engaged in collaboration with theory groups to understand the dynamical details of localized and propagating plasmons and their relationship to single-molecule Raman scattering. Our ultimate goal is a broad-based mechanistic understanding of excited-state dynamics of surface structures, plasmonics, and ultrasensitive chemical imaging. We have demonstrated single-molecule detection and designed manipulation (e.g., focusing) of propagating plasmons. Ultimately, our efforts are directed toward providing the radiation and analytical chemistry research needs required by the U.S. Department of Energy's energy and environmental restoration missions.
Currently, I am serving as Interim Director of the Physical Sciences Division.
- Laser desorption and surface modification
- Surface and tip-enhanced Raman spectroscopy
- Localized and propagating surface plasmon dynamics
Education and Credentials
- Ph.D. Physical Chemistry, University of Colorado, Boulder, CO, January, 1988
- M.S. Chemical Physics, University of Oregon, Eugene, OR, May 1983
- B.A. Chemistry, University of Colorado, Boulder, CO, May 1981.
Affiliations and Professional Service
- American Chemical Society
- American Physical Society
Awards and Recognitions
- American Physical Society Fellow, 2012
- Co-Chairman Eighth International Conference on Laser Ablation (COLA 05)
- Associate Editor: Laser Chemistry
- International Steering Committee, International Conference on Laser Ablation
- Vice-chair Gordon Research Conference: Laser Interactions with Materials