OPTICAL FILM, OPTICAL ELEMENT, MANUFACTURING METHOD THEREOF, AND PHOTOGRAPHIC OPTICAL SYSTEM

摘要

An optical film includes a fluoride layer made of a fluoride containing at least Li element and at least one kind of element selected from Mg and Al. A method for manufacturing an optical film includes allowing at least Li metal, a metal acetate or a metal alkoxide of at least one kind of metal selected from Mg and Al, and trifluoroacetic acid to react in a solvent to obtain a fluorine-containing precursor containing a metal fluorocarboxylate, and, after coating the fluorine-containing precursor on a base material, heating the fluorine-containing precursor to form a fluoride layer made of a fluoride containing at least Li element and at least one kind of element selected from Mg and Al.