Preparation of high-performance optical coatings with fluoride nanoparticle films made from autoclaved sols.
An ultralow refractive index is very advantageous when one designs antireflective coatings. We successfully obtained high-quality MgF2 thin films with ultralow refractive indices from autoclaved sols prepared from magnesium acetate and hydrofluoric acid. The MgF2 films consist of nanosized particles, and they have high laser-exposure durability at 193 nm. The reflectance of the antireflective coating with five layers, of which the top layer is formed by our method, is lower than 0.6% in the incident angle range of 0 degrees - 60 degrees at 193 nm.
Murata
Tsuyoshi
T
Department of Lens Engineering Development, Production Technology Headquarters, Core Technology Center, Nikon Corporation, 10-1, Asamizodai 1-chome, Sagamihara, Kanagawa 228-0828, Japan. murata.go@nikon.co.jp
Ishizawa
Hitoshi
H
Motoyama
Izumi
I
Tanaka
Akira
A