Glass for optical filter and optical filter

Abstract

A glass for an optical filter, the glass being a phosphate glass including Cu, in which the glass has: an average transmittance of 80% or more at a wavelength of 430 nm to 550 nm; an average transmittance of 2% or less at a wavelength of 800 nm to 950 nm; an average transmittance of 3% or less at a wavelength of 1000 nm to 1200 nm; an average transmittance of 5% or less at a wavelength of 700 nm to 1200 nm; a transmittance of 25% or more at a wavelength of 1550 nm; and a wavelength at which a transmittance is 50% of 615 nm or more in a wavelength range of 600 nm to 800 nm.

Dependencies are inferred from the claim text.