An electronic device may have a display with an array of pixels configured to display images for a user. The electronic device may have an ambient light sensor for gathering ambient light information. Control circuitry in the electronic device may adjust the brightness level of an image being displayed by the display based on ambient light measurements from the ambient light sensor. The ambient light sensor may be formed from an ambient light sensor module that is aligned with an opening in an opaque masking layer in the display. One or more antireflection layers may be interposed between an inwardly facing surface of the display and an opposing external surface of the ambient light sensor module. The ambient light sensor module may have a light attenuator and other optical structures.

An optical device comprises an optical filter having a substrate and a multilayer film, and an infrared light emitting and receiving device having a first conductive-type semiconductor layer, an active layer, and a second conductive-type semiconductor layer. The multilayer film has layers with different refractive indexes formed on at least one side of the substrate, in which first and second layers having refractive indexes of 1.2 or more and 2.5 or less, and 3.2 or more and 4.3 or less, respectively, in a wavelength range of 6 μm to 10 μm are alternately stacked. 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 6 μm to 10 μm, and has a maximum transmittance of 10% or more in a wavelength range of 12.5 μm to 20 μm.

An optical structure is provided. The optical structure includes a sensor, a bandpass filter and a plurality of protrusions. The bandpass filter is disposed above the sensor. The protrusions are disposed on the bandpass filter. The bandpass filter allows light with a wavelength of 700 nm to 3,000 nm to pass through. The protrusions have a size distribution that controls the phase of the incident light to be between 0 and 2π.

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 (I) having a maximum absorption wavelength in a wavelength of 690 to 900 nm in dichloromethane, and a resin, the optical filter transmits visible light and light in at least part of a wavelength of 900 to 1,000 nm, and the optical filter satisfies specific spectroscopic characteristics.

A bandpass filter may include a set of layers. The set of layers may include a first subset of layers. The first subset of layers may include hydrogenated germanium (Ge:H) with a first refractive index. The set of layers may include a second subset of layers. The second subset of layers may include a material with a second refractive index. The second refractive index may be less than the first refractive index.

A system may include one or both of a light emitter and a light receiver, and an optical filter. The optical filter includes a wavelength selective scattering layer. The wavelength selective scattering layer may have a near-infrared scattering ratio of less than about 0.9. The filter may have a visible reflective haze ratio of greater than about 0.5. A method may include disposing the wavelength selective scattering layer adjacent one or both of the light emitter and the light receiver. The optical filter may include a wavelength selective reflective layer. The optical filter may include a wavelength selective absorbing layer. An article may include the optical filter. The wavelength selective scattering layer may have an average near-infrared scattering of less than 60%, an average visible scattering of greater than 10%, and a difference between the % total visible reflectance and the % diffuse visible reflectance of less than 20.

A display system includes a display panel configured to emit polarized light having a first polarization state and substantially distinct blue, green and red emission spectra having respective blue, green and red full widths at half maxima (FWHMs). The display system includes a reflective polarizer configured to reflect the polarized image light as a first reflected polarized image light. For substantially normally incident light and for the first polarization state, the reflective polarizer has a reflectance of greater than about 60% across each of the blue and red FWHMs, and a transmittance of at least about 50% for at least a first wavelength between the FWHMs of the blue and green emission spectra, and for at least a second wavelength between the FWHMs of the green and red emission spectra.

An optical apparatus includes an optical system for outputting parallel light, and an angle filter disposed on an optical path of the parallel light output from the optical system. The angle filter includes a dielectric multilayer film in which dielectric layers having a first refractive index n.sub.1 and dielectric layers having a second refractive index n.sub.2 lower than the first refractive index n.sub.1 are alternately stacked.

An imaging device for imaging of a local area surrounding the imaging device. The imaging device includes a lens assembly, a filtering element and a detector. The lens assembly is configured to receive light from a local area surrounding the imaging device and to direct at least a portion of the received light to the detector. The filtering element is placed in the imaging device within the lens assembly such that light is incident at a surface of the filtering element within a range of angles determined by a design range of angles at which the filtering element is designed to filter light. The detector is configured to capture image(s) of the local area including the filtered light. The imaging device can be integrated into a depth camera assembly for determining depth information of object(s) in the local area based on the captured image(s).

An optical-thin-film structure comprises a low-index optical thin film consisting essentially of co-deposited Barium Fluoride and a secondary fluoride compound, and a high-index optical thin film.