Secondary Spin-Coating Enhances MgF2 Antireflection Coating
The technology used to apply antireflection coatings to glass is well-established. In its simplest form, the coating has one layer of material, usually a dielectric, with an optical thickness of λ/4, where the lowest amount of reflection at the surface is desired. The addition of a secondary spin-coated silica layer enhances these properties for specific applications.
Ideally, an antireflection coating should have a refractive index equal to the square root of the index of the glass...
Photonics Spectra, July 2004