Optical multi-layer thin film, optical element, and method for producing the optical multi-layer thin film

摘要

Optical multi-layer thin film comprises: an outermost layer stacked above an optical surface of an optical substrate having a lower refractive index than the optical substrate; and at least a certain refractive index layer disposed between the optical substrate and the outermost layer, and having a refractive index adjustable in a predetermined range higher than that of the outermost layer. The outermost layer is formed by a wet film-formation method using: low-refractive-index fine particles made of a low-refractive-index material; and a first binder, and the certain refractive index layer is formed by a wet film-formation method using: high-refractive-index fine particles made of a high-refractive-index material; and a second binder which has a refractive index different from that of the high-refractive-index material.