Application of Diamond-like Films for Improving Transparency in the IR

Paper presents the Diamond-Like Carbon (DLC) to create achromatic antireflective coating for improving transparency of the Ge optical elements in the IR. Constructions of the interference achromatic multilayered coatings (MLC) with protective DLC films on their surfaces for germanium optical elements have been calculated by computer simulation method using OptiLayer software complex. The films were deposited by plasma-enhanced chemical vapor deposition (PECVD) in the methane_hydrogen atmosphere (methane content in gas admixture was 50 vol. %) at mean ion energy in the discharge gap of plasma-chemical reactor within 30 – 80 eV. The protective 70 – 200 nm thick DLC films were shown to do not worse the transparency of multilayered coatings in the region from 700cm−1 to 1400 cm−1. The mechanical durability of coat corresponds to ”0”group of 3-1901-85.