Antireflection film and optical element having the same

摘要

An antireflection film includes alternately deposited high-refractive-index layers and low-refractive-index layers. The refractive indexes and extinction coefficients of the layers are such that the antireflection film exhibits sufficient antireflection characteristics even if the geometrical thickness thereof is small. An optical element having the antireflection film on a substrate exhibits high transmittance and has excellent optical characteristics.