The effect of hydrogen concentration in conventional and IAD coatings on the absorption and laser-induced damage at 10.6 μm
SPIE Proceedings Vol. 1848: Laser-Induced Damage in Optical Materials
335
1992
Type: Zeitschriftenaufsatz (non-reviewed)
DOI: 10.1117/12.147408
Abstract
In this paper, data of single layers of YbF3, BaF2, YF3, and NaF and multilayer coatings produced by conventional thermal evaporation (boat, e-beam) and ion assisted deposition (IAD) are compared. Hydrogen concentration depth profiling was performed using nuclear reaction analysis based on the reaction 1H(15N, (alpha) (gamma) )12C. Absorption was measured with the aid of a laser calorimeter and a cw CO2 laser. A computer-controlled test facility with a TEA CO2 laser was used for determining the 1-on-1 damage thresholds of the coatings. The results point out that the absorption and damage behavior of coatings for the CO2 laser wavelength are related to the total amount of species containing hydrogen. Most of the IAD coatings exhibit a lower hydrogen contamination than conventional thin films.