Antireflection coatings for ultraviolet radiation obtained by molecular beam deposition

Fluoride antireflection coatings on MgF2 substrates for a wavelength of 248 nm have been deposited by molecular beam deposition. Transmission and laser induced damage threshold of the samples have been measured and AFM investigations have been carried out. A 14-layer design for AR coatings with sublayer thicknesses of 12 nm is compared with a conventional 2-layer design with quarter wavelength thicknesses. The laser induced damage threshold of the 14-layer coating is slightly higher than that of the 2-layer coating. AFM surface images show that the 14-layer coating has a smoother surface than the 2-layer-coating.