Abstract: A side window cap is configured to cover and seal a light emitting element onto a substrate where the light emitting element is mounted. The side window cap has a cross sectional shape of an inverted recess having an upper wall portion, four side wall portions, and a lower opening. One of the four side wall portions is a window made of a transparent material. Three of the four side wall portions and the upper wall portion are made of glass ceramic. The transparent material and the glass ceramic are directly bonded.

Abstract: An optical filter includes: an absorption layer including a first near-infrared absorbing dye (D1), a second near-infrared absorbing dye (D2), and a transparent resin; and a reflection layer including a dielectric multilayer film. The dye (D1) and the dye (D2) are squarylium compounds satisfying following (1) to (3). (1) The dye (D1) has a maximum absorption wavelength ?max(D1) within a range of 680 to 730 nm, and the difference between a wavelength at which a transmittance is 80% on the shorter wavelength side than ?max(D1) when the concentration is adjusted such that a transmittance at ?max(D1) is 10%, and ?max(D1) is 100 nm or less. (2) The dye (D2) has a maximum absorption wavelength ?max(D2) within a range of 720 to 770 nm. (3) A value obtained by subtracting ?max(D1) from ?max(D2) is 30 nm or more and 85 nm or less.

Abstract: A diepoxy compound represented by the following formula 1, where any one of R1 groups is an epoxy group, and the remaining R1 groups each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, and any one of R2 groups is an epoxy group, and the remaining R2 groups each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms.

Abstract: An optical filter includes: an absorption layer including a first near-infrared absorbing dye (D1), a second near-infrared absorbing dye (D2), and a transparent resin; and a reflection layer including a dielectric multilayer film. The dye (D1) and the dye (D2) are squarylium compounds satisfying following (1) to (3). (1) The dye (D1) has a maximum absorption wavelength ?max(D1) within a range of 680 to 730 nm, and the difference between a wavelength at which a transmittance is 80% on the shorter wavelength side than ?max(D1) when the concentration is adjusted such that a transmittance at ?max(D1) is 10%, and ?max(D1) is 100 nm or less. (2) The dye (D2) has a maximum absorption wavelength ?max(D2) within a range of 720 to 770 nm. (3) A value obtained by subtracting ?max(D1) from ?max(D2) is 30 nm or more and 85 nm or less.

Abstract: An optical filter including: a substrate; and a dielectric multilayer film laid on or above at least one major surface of the substrate as an outermost layer, in which the substrate includes a resin film including a dye (IR) and a resin, the dye (IR) has a maximum absorption wavelength in a wavelength of 680 to 800 nm in the resin, and the optical filter satisfies specific spectroscopic characteristics.

Abstract: An optical filter includes: an absorption layer including a first near-infrared absorbing dye (D1), a second near-infrared absorbing dye (D2), and a transparent resin; and a reflection layer including a dielectric multilayer film. The dye (D1) and the dye (D2) are squarylium compounds satisfying following (1) to (3). (1) The dye (D1) has a maximum absorption wavelength ?max(D1) within a range of 680 to 730 nm, and the difference between a wavelength at which a transmittance is 80% on the shorter wavelength side than ?max(D1) when the concentration is adjusted such that a transmittance at ?max(D1) is 10%, and ?max(D1) is 100 nm or less. (2) The dye (D2) has a maximum absorption wavelength ?max(D2) within a range of 720 to 770 nm. (3) A value obtained by subtracting ?max(D1) from ?max(D2) is 30 nm or more and 85 nm or less.

Abstract: An optical filter includes: an absorption layer including a first near-infrared absorbing dye (D1), a second near-infrared absorbing dye (D2), and a transparent resin; and a reflection layer including a dielectric multilayer film. The dye (D1) and the dye (D2) are squarylium compounds satisfying following (1) to (3). (1) The dye (D1) has a maximum absorption wavelength ?max(D1) within a range of 680 to 730 nm, and the difference between a wavelength at which a transmittance is 80% on the shorter wavelength side than ?max(D1) when the concentration is adjusted such that a transmittance at ?max(D1) is 10%, and ?max(D1) is 100 nm or less. (2) The dye (D2) has a maximum absorption wavelength ?max(D2) within a range of 720 to 770 nm. (3) A value obtained by subtracting ?max(D1) from ?max(D2) is 30 nm or more and 85 nm or less.