There is provided an imaging device, an electronic apparatus including an imaging device, and an automotive vehicle including an electronic apparatus including an imaging device, including: a first substrate including a first set of photoelectric conversion units; a second substrate including a second set of photoelectric conversion units; and an insulating layer between the first substrate and the second substrate; where the insulating layer has a capability to reflect a first wavelength range of light and transmit a second wavelength range of light that is longer than the first wavelength range of light.

An optical filter includes a substrate and a dielectric multilayer film laid as an outermost layer on at least one major surface of the substrate. The dielectric multilayer film includes a low-refractive index film and a high-refractive index film provided alternately. At least one film selected from the group consisting of the low-refractive index film and the high-refractive index film satisfies the following optical characteristics (i-1) and (i-2A): (i-1) an extinction coefficient k.sub.600 at a wavelength of 600 nm is 0.12 or larger; and (i-2A) a minimum extinction coefficient k.sub.1530-1570MIN in a wavelength range of 1530 to 1570 nm is 0.01 or smaller; and the optical filter satisfies the following optical characteristic (ii-1A): (ii-1A) light in a wavelength range of 400 to 680 nm is blocked and light in the wavelength range of 1530 to 1570 nm is transmitted.

An interference filter includes a layers stack comprising a plurality of layers of at least: layers of amorphous hydrogenated silicon with added nitrogen (a-Si:H,N) and layers of one or more dielectric materials, such as SiO.sub.2, SiO.sub.x, SiO.sub.xN.sub.y, a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive, or so forth. The interference filter is designed to have a passband center wavelength in the range 750-1000 nm inclusive. Added nitrogen in the a-Si:H,N layers provides improved transmission in the passband without a large decrease in refractive index observed in a-Si:H with comparable transmission. Layers of a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive provide a smaller angle shift compared with a similar interference filter using SiO.sub.2 as the low index layers.

According to an embodiment of the disclosure, an electronic device includes a light source unit to emit infrared light having a specified wavelength band, a camera module, a memory, and a processor, the camera module includes a lens assembly including a first lens having a property to at least partially absorb visible light and one or more second lenses to refract light, which is output through the first lens, at a specified angle, a filter to pass through light, which has the specified wavelength band, of the light output through the lens assembly, and an image sensor to sense light, which is output through the lens assembly and the filter, to obtain an image, and the processor is configured to receive an input of a user to photograph an external object, emit the infrared light using the light source unit based on the input of the user, and obtain, using the camera module, an image corresponding to light, which is reflected from the external object, of the emitted infrared light.

A method for manufacturing hybrid optical coatings and hybrid mirror assemblies, including: a) providing a first optical coating having layers of alternating high and low refractive indices of crystalline materials on a first host substrate via an epitaxial growth technique; b) providing a second optical coating having layers of alternating high and low refractive indices of dielectric materials on a second host substrate via a physical vapor deposition (PVD) technique; c) directly bonding the first optical coating to the second optical coating; and d) removing the first host substrate.

A tunable optical filter comprises a resonant grating layer having an aperiodic pattern, an optional sublayer, a waveguide layer, and a substrate layer, wherein at least one of the waveguide layer and the sublayer, when present is inhomogenous. In some instances, the optional sublayer and/or the waveguide layer may comprise a thickness gradient. Incident light may be filtered and/or reflected by an optical filter, for instance a band of incident electromagnetic radiation has 90% or greater transmittance or reflectance and adjacent bands of incident electromagnetic radiation have 10% or less transmittance or reflectance, respectively.

This disclosure provides a highly accurate NDIR gas sensor and a highly accurate optical device even using a simplified optical filter. The NDIR gas sensor and the optical device include: an optical filter having a substrate and a multilayer film on the substrate; and an infrared light emitting and receiving device; where the multilayer film has a structure in which a first layer and a second layer are alternately stacked; the active layer contains Al.sub.xIn.sub.1-xSb or InAs.sub.ySb.sub.1-y; 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 2400-6000 nm, and has a maximum transmittance of 5% or more in 6000-8000 nm and an average transmittance of 2% or more and 60% or less in 6000-8000 nm.

Infrared reflectors are described. In particular, infrared reflectors with reduced off-axis color are described. Such infrared reflectors may be useful in laminated glass constructions, particularly for applications where the glass may be exposed to water.

Light-absorbing flange lenses that may be used in the lens stacks of compact lens systems. In a light-absorbing flange lens, the effective area of the lens is composed of a transparent optical material, and at least a portion of the flange of the lens is composed of an optical material that absorbs at least a portion of the light that enters the flange. Using light-absorbing flange lenses may allow the lens barrel to be eliminated from the lens system, thus reducing the X-Y dimensions of the lens system when compared to conventional compact lens systems that include a lens stack enclosed in a lens barrel. In addition, using a light-absorbing material in the flanges of the light-absorbing flange lenses may reduce or eliminate optical aberrations such as lens flare, haze, and ghosting in images.

An optical lens assembly includes at least three optical lens elements. At least one of the optical lens elements includes an infrared filtering coating, the optical lens element including the infrared filtering coating is made of a plastic material, the infrared filtering coating is arranged on an object-side surface or an image-side surface of the optical lens element, a surface of the optical lens element including the infrared filtering coating is aspheric, and the infrared filtering coating includes at least two different refractive indices. At least one of the optical lens elements includes a long-wavelength absorbing material, and the optical lens element including the long-wavelength absorbing material is made of a plastic material.