ANTIREFLECTION FILM, AND OPTICAL ELEMENT AND OPTICAL SYSTEM THAT INCLUDE THE SAME

摘要

An antireflection film formed on a substrate having a refractive index between 1.40 and 1.85 inclusive for light having a wavelength of 550 nm includes an intermediate layer formed on the substrate, and a concavo-convex layer formed on the intermediate layer, the concavo-convex layer includes a part has a refractive index that continuously increases from a side closer to a surface toward a side closer to the substrate, the intermediate layer includes a plurality of thin film layers having different refractive indices, and at least one of the thin film layers has a refractive index higher than the refractive index of the substrate, and the thin film layers include a first layer formed on the substrate and having a physical thickness d1, and a second layer formed on the first layer and having a physical thickness d2, and satisfy predetermined conditional expressions.

主权项

1. An antireflection film formed on a substrate having a refractive index between 1.40 and 1.85 inclusive for light having a wavelength of 550 nm, the antireflection film comprising:
an intermediate layer formed on the substrate; and a concavo-convex layer formed on the intermediate layer, wherein: the concavo-convex layer includes a part having a refractive index that continuously increases from a side closer to a surface toward a side closer to the substrate, the intermediate layer includes a plurality of thin film layers having different refractive indices, and at least one of the thin film layers has a refractive index higher than the refractive index of the substrate, and the thin film layers include: a first layer formed on the substrate and having a physical thickness d1 (nm), and a second layer formed on the first layer and having a physical thickness d2 (nm), and satisfy conditional expressions below:
ns