Patent ID: 11921038
Assignee: ASAHI KASEI MICRODEVICES CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 15:
16. An optical device comprising:
an optical filter having a substrate and a multilayer film having a plurality of layers with different refractive indexes formed on at least one side of the substrate; and
an infrared light emitting and receiving device having a semiconductor layer of a first conductive type, an active layer, and a semiconductor layer of a second conductive type; wherein
the multilayer film has a structure in which a first layer and a second layer are alternately stacked, the first layer contains at least one selected from the group consisting of SiO, SiO2, TiO2 and ZnS, and the second layer contains at least one selected from the group consisting of Si and Ge; and
the optical filter includes a wavelength range having an average transmittance of 70% or more with a width of 50 nm or more in a wavelength range of 2400 nm to 6000 nm, and has a maximum transmittance of 5% or more in a wavelength range of 6000 nm to 8000 nm.