Optical filter

The present invention relates to an optical filter provided with a substrate and a dielectric multilayer film laminated as the outermost layer on at least one main surface side of the substrate, the dielectric multilayer film being a laminate in which a low-refractive-index film and a high-refractive-index film are laminated, the extinction coefficient (k600) of either the low refractive index film or the high refractive index film at a wavelength of 600 nm is 0.12 or more and the minimum extinction coefficient (k800-1570MIN) in a wavelength region of 800-1570 nm is 0.01 or less, or the spin density is 5.0 * 1010 (pieces/(nm * cm2)) or more, the optical filter satisfies all specific spectral characteristics (ii-1)-(ii-3), and the nanoindentation hardness is 5.5 GPa or more at a measurement load of 1 mN. 本发明涉及一种光学滤波器，具备基材、以及在上述基材的至少一个主面侧作为最外层而层叠的电介质多层膜的光学滤波器，上述电介质多层膜为层叠低折射率膜与高折射率膜而成的层叠体，上述低折射率膜和上述高折射率膜中的任一者的波长600nm的消光系数k600为0.12以上且800～1570nm的波长区域的最小消光系数k800－1570MIN为0.01以下，或者自旋密度为5.0×1010(个/(nm*cm2))以上，上述光学滤波器满