Ultraviolet optical properties of MgF2 coatings deposited by resistance boat evaporation at different temperatures

摘要

Single layers of MgF_2 were deposited upon super polished fused-silica substrates by resistance boat evaporation at different temperatures. The transmittance and reflectance spectra were measured and the optical losses were analyzed. The laser-induced damage thresholds (LIDT) were characterized at the wavelength of 355nm for certain samples. The absorbance of the samples was discussed related to the LIDT. The increasing absorbance with the higher deposited temperature was attributed to the decreasing of the LIDT. And the high micro-defect density of the sample surface resulted in the low LIDT.