Abstract: An optical filter, includes: a near infrared ray absorbing glass, dielectric multilayer films laid on or above both major surfaces of the near infrared ray absorbing glass, and an absorption layer laid on or above a surface of at least one of the dielectric multilayer films and having a maximum absorption wavelength in a near infrared light region, in which the optical filter satisfies all of spectral characteristics (i-1) to (i-5).

Abstract: An optical filter, includes: a substrate, a dielectric multilayer film 1 laid on or above one major surface of the substrate, and a dielectric multilayer film 2 laid on or above the other major surface of the substrate, in which the substrate includes a near infrared ray absorbing glass and a resin film, the resin film includes a resin and a pigment (NIR1), and the optical filter satisfies all of spectral characteristics (i-1) to (i-5), (i-7) to (i-10), (i-12) and (i-14).

Abstract: A transmitting diffraction element may include a transparent substrate, and a plurality of convex parts periodically formed on one surface of the transparent substrate, and be configured to diffract incident light to the transparent substrate. Each of the convex parts may include first, second, third, and fourth layers that are stacked on the transparent substrate. The first and third layers may be made of a material having a high refractive index, and the second and fourth layers may be made of a material having a low refractive index that is lower than the high refractive index.

Abstract: A transmitting diffraction element may include a transparent substrate, and a plurality of convex parts periodically formed on one surface of the transparent substrate, and be configured to diffract incident light to the transparent substrate. Each of the convex parts may include first, second, third, and fourth layers that are stacked on the transparent substrate. The first and third layers may be made of a material having a high refractive index, and the second and fourth layers may be made of a material having a low refractive index that is lower than the high refractive index.