Open AccessExterior surface damage of calcium fluoride outcoupling mirrors for DUV lasers
Author(s) -
Michael Bauer,
Martin Bischoff,
Sigrid Jukresch,
Thomas Hülsenbusch,
Ansgar Matern,
A. Görtler,
Robert W. Stark,
Andrey Chuvilin,
Ute Kaiser
Publication year - 2009
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.008253
Subject(s) - laser , materials science , optics , irradiation , radiation , optoelectronics , ultraviolet , physics , nuclear physics
Damage of optical components due to laser irradiation reduces reliability and limits durability. Calcium fluoride (CaF(2)) is commonly used for deep UV laser optics because it shows a very low tendency of color center formation as, compared to other UV-X optical materials. Here, we report on the exterior damage of CaF(2) UV-X optics due to radiation with high pulse-energy densities (80 mJ/cm(2)) from an ArF laser. At such high energy densities, damage occurs on the external resonator side. The damage is generated by a partial alteration of the CaF(2) substrate to crystalline CaCO(3) (calcite). The decomposition of CaF(2) is mainly driven by photochemical processes in the presence of water vapor, which are induced by the UV-laser light and the elevated temperature within the beam profile.