The invention relates to a diffuser 3 intended to be facing a light source 1 comprising a transmission layer 10 and a diffusion layer 22, 23 intended to diffuse a light transmitted by the light source, the diffuser being characterised in that the diffusion layer comprises a plurality of metal structures 200, 200a, 200b, called metal nanostructures, having dimensions less than a wavelength of the light transmitted, said metal nanostructures having varied sizes and being distributed within the diffusion layer such that adjacent metal nanostructures have between them, varied distances and preferably less than the wavelength of the light transmitted. The invention also relates to a method for manufacturing such a diffuser, and a display system comprising such a diffuser.

A distance measuring camera apparatus according to an embodiment of the present invention comprises: a light-emitting unit; and a light-receiving unit including an image sensor. The light-emitting unit comprises: a light source including a light-emitting device; and a diffusion member arranged on the light source and including a plurality of micro-lenses. The diffusion member includes a first region and a second region, wherein the first region surrounds the second region and the second region is arranged such that the center thereof overlaps the light-emitting unit in an optical axis direction. In addition, the diameter of the micro-lens in the second region is smaller than the diameter of the micro-lens in the first region.

Optical spectrometers may be used to determine the spectral components of electromagnetic waves. Spectrometers may be large, bulky devices and may require waves to enter at a nearly direct angle of incidence in order to record a measurement. What is disclosed is an ultra-compact spectrometer with nanophotonic components as light dispersion technology. Nanophotonic components may contain metasurfaces and Bragg filters. Each metasurface may contain light scattering nanostructures that may be randomized to create a large input angle, and the Bragg filter may result in the light dispersion independent of the input angle. The spectrometer may be capable of handling about 200 nm bandwidth. The ultra-compact spectrometer may be able to read image data in the visible (400-600 nm) and to read spectral data in the near-infrared (700-900 nm) wavelength range. The surface area of the spectrometer may be about 1 mm.sup.2, allowing it to fit on mobile devices.

The present invention addresses the problem of providing a transparent article in which sparkling on an anti-glare surface or other roughened relief surface is suppressed. The transparent article is provided with a transparent substrate, and a roughened relief surface provided to at least one surface of the transparent substrate. The relief surface has a surface roughness Sq of 50 nm or less measured in a spatial period of 20 μm or greater in the transverse direction.

An optical film for a back light unit that includes an array of light emitting diodes. The optical film includes a substrate, and a plurality of regions of spatially modulated microstructures on at least one side of the substrate. The spatially modulated microstructures have different sizes and/or shapes configured to create a gradient structure within each region. The gradient structure within each region is constructed and arranged to cause more spreading of light when positioned directly above an individual light emitting diode and less spreading of light at locations not directly above an individual light emitting diode. Within the back light unit, the gradient structure converts light beams emitted by the respective light emitting diode at different angles into a more uniform and higher on-axis luminance upon exiting the back light unit.

A focusing device includes a substrate and a plurality of scatterers provided at both sides of the substrate. The scatterers on the both sides of the focusing device may correct geometric aberration, and thus, a field of view (FOV) of the focusing device may be widened.

Provided is a light source system, including: a light-emitting module configured to emit first light along a first light path and second light along a second light path; a wavelength conversion device configured to receive the first light and emit excited light with a color different from the first light; and a compensation device configured to guide the second light and adjust its luminous intensity distribution so that the luminous intensity distribution of the second light exiting from the compensation device is substantially identical to the excited light. The compensation device includes a compensation element configured to adjust luminous intensity distribution of a light beam so that an emergent light beam of the compensation element has reduced overall luminous intensity compared with an incident light beam. The second light exiting from the compensation device is combined with the excited light to form third light.

An image-capturing device includes: an illumination light source configured to emit illumination light to illuminate an object; a laser light source configured to emit laser light with a peak wavelength in a range of wavelengths absorbed or reflected by at least one region of the object; an imaging device configured to take an image of the object; a speckle variable device configured to change a speckle pattern in an image acquired by the imaging device over time; and an image processing device configured to process the image acquired by the imaging device, which includes: measuring a change over time in a intensity signal from each pixel constituting the image, and dividing an imaged region of the object into a plurality of portions based on a waveform of the change in the intensity signal over time.

A privacy display comprises a polarised output spatial light modulator, reflective polariser, plural polar control retarders and a polariser. A birefringent surface relief diffuser structure is arranged to transmit light from the display with high transparency and provide diffuse reflection of ambient light to head-on display users. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss and with low diffusion, whereas off-axis light has reduced luminance and increased diffusion. Further, overall display reflectivity is reduced for on-axis reflections of ambient light, while reflectivity is increased for off-axis light. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction, increased frontal reflectivity and diffusion of ambient light. In a public mode of operation, the liquid crystal retardance is adjusted so that off-axis luminance and reflectivity are unmodified.

Optical spectrometers may be used to determine the spectral components of electromagnetic waves. Spectrometers may be large, bulky devices and may require waves to enter at a nearly direct angle of incidence in order to record a measurement. What is disclosed is an ultra-compact spectrometer with nanophotonic components as light dispersion technology. Nanophotonic components may contain metasurfaces and Bragg filters. Each metasurface may contain light scattering nanostructures that may be randomized to create a large input angle, and the Bragg filter may result in the light dispersion independent of the input angle. The spectrometer may be capable of handling about 200 nm bandwidth. The ultra-compact spectrometer may be able to read image data in the visible (400-600 nm) and to read spectral data in the near-infrared (700-900 nm) wavelength range. The surface area of the spectrometer may be about 1 mm.sup.2, allowing it to fit on mobile devices.