Femtosecond Time-Resolved Photo-Stimulated Desorption from Ionic Crystals

Journal Article · Mon Jan 28 04:00:00 EST 2002 · Applied Surface Science

DOI:https://doi.org/10.1016/S0169-4332(01)00670-5· OSTI ID:15001391

Joly, Alan G ^[1]; Hess, Wayne P ^[1]; Beck, Kenneth M ^[1]; Dickinson, J T ^[2]

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1. BATTELLE (PACIFIC NW LAB)
2. 8392

We have used the pump-probe technique to measure the positive ion yield, from ionic crystals, as a function of time-delay between two femtosecond laser pulses. The two-pulse technique allows direct observation of solid state and surface dynamics on a femtosecond timescale. We find the ion yield, from 265 nm irradiated MgO and KBr, depends critically on the time delay between pulses. For example, the Mg+ desorption yield displays three distinct features; a coherence peak followed by a fast rise and decay features. In contrast, the yield of K+ from KBr displays only the coherence peak and picosecond decay features. The observed thresholds suggest that, although the nanosecond laser ion desorption mechanism may be dominated by defect photoabsorption, significant electron-hole pair production may contribute to the femtosecond laser desorption mechanism. By determining the ultrafast time-dependence we hope to reveal the mechanism of the laser ion desorption for both regimes.

• Research Organization: Pacific Northwest National Lab., Richland, WA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 15001391
• Report Number(s): PNNL-SA-34867; KC0301020
• Journal Information: Applied Surface Science, Journal Name: Applied Surface Science Journal Issue: 1-4 Vol. 186
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CATIONS
DECAY
DEFECTS
DESORPTION
IONIC CRYSTALS
LASERS
PAIR PRODUCTION
TIME DELAY
TIME DEPENDENCE