GLASS SUBSTRATE FOR MULTILAYER FILM OPTICAL FILTER, MULTILAYER FILM OPTICAL FILTER, AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a thin glass substrate optimum for multilayer film optical filter, a method for producing multilayer film optical filter by which the man- hour of polishing is reduced, and to provide a multilayer film optical filter in which internal stress stored in film formation is controlled to <=±100 MPa. SOLUTION: The glass substrate for a multilayer film optical fiber comprising a dielectric multilayer film obtained by alternately stacking a plurality of high refractive index films and low refractive index films has >=80 mm maximum diameter and <=2 mm thickness.