Tunable filters can use Fano metasurface designs having extremely narrow transmission bands. The Fano metasurface can comprise dielectric or semiconductor materials and can produce transmission bands with quality factors well in excess of 1000—at least a factor of 50 greater than typical metamaterial-based infrared resonances. Numerical simulations of these metasurfaces show that the spectral position of the passband can be changed by slightly changing the position of a small dielectric perturbation block placed within the near-field of the resonator by using simple electromechanical actuation architectures that allow for such motion. An array of independently tunable narrowband infrared filters can thereby be fabricated that only requires deep-subwavelength motions of perturbing objects in the resonator's near-field.

The arrangement comprises a filter region (10) filtering electromagnetic radiation and a shielding component (20) inhibiting propagation of electromagnetic radiation. The filter region comprises a central filter region (11) and a separate peripheral filter region (13). The shielding component comprises an aperture (21). The aperture is arranged above the central filter region. The central filter region and the peripheral filter region are optimized for different angles of incidence (α, β) and provided for measurements by individual sensor regions (18, 19).

According to one aspect, the invention relates to an angular optical filtering element (E.sub.i) optimized for angular filtering about a given operating angle of incidence (θ.sub.i, 1) in a given spectral band. The angular filtering element (E.sub.i) comprises a first nanostructured, band-pass, spectral filter (11.sub.i, 301) and a second nanostructured, band-pass, spectral filter (12.sub.i, 302). Each of the first and second spectral filters comprises, respectively, in said spectral band, a first and a second central filtering wavelength that respectively has a first and second angular dispersion curve defined depending on the angle of incidence (θ.sub.inc) on the optical filtering element (E.sub.i), the curves of angular dispersion being secant about the operating angle of incidence (θ.sub.i, 1) of the optical filtering element. The invention applies to the production of a selective angular filtering device and to a multidirectional optical detection system.

A spectral imager includes a filter array, a pixel array, and a lenslet array therebetween. The filter array includes a plurality of filter regions. The lenslet array includes a plurality of lenslets each configured to form a respective image of the filter array on a respective one of a plurality of regions of the pixel array. The spectral imager may also include a fore-optic lens, the filter array being located between the lenslet array and the fore-optic lens. The spectral imager may also include a fore-optic lens, the filter array being located between the lenslet array and the fore-optic lens. Each of the plurality of filter regions is configured to selectively transmit radiation based on wavelength and/or polarization.

Lens coatings and coated lenses which offer full-spectrum protection by reducing back-side reflection of all light spanning from the ultraviolet sub-band B (UVB) to infrared (IR-A) region are provided. The full-spectrum back-side anti-reflective coatings disclosed herein are comprised of multiple thin-film layers of high refractive index (HighIndex) and low refractive index (LowIndex) materials. In many embodiments, the penultimate layer distal from the substrate lens is a HighIndex layer, and the final layer distal from the substrate lens is a LowIndex layer.

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.

A sputtering system may include a substrate. The sputtering system may include at least one target. The at least one target may include at least one coating material to coat at least one layer onto the substrate. The at least one coating material may be sputtered onto the substrate in a presence of an inert gas. The inert gas may include argon gas and helium gas.

A texture recognition device and a display device are provided. The texture recognition device includes a backlight element, configured to provide first backlight; a light constraint element, configured to perform a light divergence angle constraint process on the first backlight to obtain second backlight with a divergence angle within a preset angle range, the second backlight being transmitted to a detection object; and a photosensitive element, configured to detect the second backlight reflected by a texture of the detection object to recognize a texture image of the texture of the detection object.

An optical filter having a passband at least partially overlapping with a wavelength range of 800 nm to 1100 nm is provided. The optical filter includes a filter stack formed of hydrogenated silicon layers and lower-refractive index layers stacked in alternation. The hydrogenated silicon layers each have a refractive index of greater than 3 over the wavelength range of 800 mn to 1100 nm and an extinction coefficient of less than 0.0005 over the wavelength range of 800 nm to 1100 nm.

A system may include one or both of a light emitter and a light receiver. The system may include an optical filter adjacent one or both of the light emitter or the light receiver. 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. 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.