Decomposition of KH{sub 2}PO{sub 4} crystals during laser-induced breakdown
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551-0808 (United States)
The structure of KH{sub 2}PO{sub 4} single crystals (so-called KDP) irradiated with {approx}3 ns, 355 nm laser pulses with fluences above the laser-induced breakdown threshold is studied by a combination of Raman scattering, photoluminescence, and soft x-ray absorption spectroscopies. We compare spectra from the as-grown material, surface and bulk laser-induced damage sites, as well as from KPO{sub 3} references. Results show that irradiation with fluences above the laser-induced breakdown threshold leads to decomposition of KDP at surface damage sites but not at bulk damage sites. New spectroscopic features are attributed to dehydration products. For the laser irradiation conditions used in this study, the decomposed near-surface layer absorbs photons at {approx}3.4 eV (364 nm). These results may explain the recently reported fact that surface laser damage sites in KDP crystals tend to grow with subsequent exposure to high-power laser pulses, while bulk damage sites do not.
- OSTI ID:
- 20702378
- Journal Information:
- Applied Physics Letters, Vol. 86, Issue 17; Other Information: DOI: 10.1063/1.1921349; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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