AVS 52nd International Symposium
    Surface Science Tuesday Sessions
       Session SS3-TuA

Paper SS3-TuA3
Ultrafast Laser Modification of Single Crystal MgO Surfaces@footnote 1@

Tuesday, November 1, 2005, 2:40 pm, Room 206

Session: Ultrafast Surface Dynamics
Presenter: J.T. Dickinson, Washington State University
Authors: J.T. Dickinson, Washington State University
S.C. Langford, Washington State University
W.P. Hess, Pacific Northwest National Laboratory
L.A. Boatner, Oak Ridge National Laboratory
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Interactions between wide bandgap insulators and nanosecond pulses of laser light at sub bandgap wavelengths often require defects for both absorption and emission. With ultrafast pulses, multiphoton absorption across the bandgap is much more probable and often yields exciton mediated decomposition. The doubly charged lattice of materials like MgO strongly inhibits exciton-induced decomposition. We compare the response of (100) MgO to 100 fs pulses at wavelengths of 800, 400, and 267 nm with our earlier studies using nanosecond pulses at 248 nm and 193 nm, where the latter interactions were clearly defect-mediated. Surfaces modified by femtosecond pulses show evidence for both photothermal and photoelectronic processes when examined by AFM and SEM. Some of these processes are clearly mediated by defects. @FootnoteText@ @footnote 1@This work was supported by the Department of Energy.