An optical element (e.g., a lens) may include an optically uniaxial or optically biaxial organic solid, for example, an organic molecular solid. The direction of a maximum refractive index of the organic solid may be aligned substantially orthogonal to an optical axis of the lens. In some examples, a device may include a display and an optical configuration configured to receive light from the display and direct the light to a remote view location. In some examples, the optical configuration may comprise a lens and at least one surface of the lens may include a plurality of facets, for example, to form a Fresnel lens.

A sub-wavelength grating optical film comprises a plurality of one-dimensional periodic grating units repeatedly arranged side by side. Each grating unit with a period of p comprises a first medium, a second medium, a third material, a fourth material, a fifth material, a sixth medium and a seventh medium, wherein the sixth medium serving as a substrate and the seventh medium serving as a covering layer are respectively arranged on bottom and top of each grating unit periodically arranged side by side. By controlling grating period and refractive index, incident blue-violet light meets condition that a diffraction angle in a layer with highest refractive index is smaller than 90 degrees; and by adjusting duty ratio of the grating and the thickness of each layer of material, transmitted light energy of the blue-violet light wave band is the lowest so that harmful blue-violet light is isolated.

Provided is a color transformation filter including a plurality of nanostructures included in a subpixel and spaced apart from each other, the plurality of nanostructures having a first refractive index, a low refractive index layer provided adjacent to the plurality of nanostructures, the low refractive index layer having a second refractive index less than the first refractive index, and a color transformation element included in the low refractive index layer.

Provided is an ATR prism, including a material having an internal transmittance of 90% or higher at a wavelength falling within a wavelength range of from 8 μm to 10 μm, when the material has a thickness of 2 mm. The ATR prism includes: a first surface including a first totally reflecting surface; a second surface including a second totally reflecting surface; and a recessed portion formed in one of the first surface or the second surface.

Provided is an ATR prism, including a material having an internal transmittance of 90% or higher at a wavelength falling within a wavelength range of from 8 μm to 10 μm, when the material has a thickness of 2 mm. The ATR prism includes: a first surface including a first totally reflecting surface; a second surface including a second totally reflecting surface; and a recessed portion formed in one of the first surface or the second surface.

The present disclosure provides a display panel, including: a first base; a plurality of light-emitting devices on the first base; a lens layer including a plurality of lenses located on a side of the plurality of light-emitting devices away from the first base and configured to converge light beams emitted from the plurality of light-emitting devices, the plurality of lenses being one-to-one correspondence with the plurality of light-emitting devices; and a filter layer located on a side of the lens layer away from the first base and configured to enable light from the plurality of light-emitting devices to form monochromatic light after the light from the plurality of light-emitting devices passes through the filter layer.

The present disclosure provides a display panel, including: a first base; a plurality of light-emitting devices on the first base; a lens layer including a plurality of lenses located on a side of the plurality of light-emitting devices away from the first base and configured to converge light beams emitted from the plurality of light-emitting devices, the plurality of lenses being one-to-one correspondence with the plurality of light-emitting devices; and a filter layer located on a side of the lens layer away from the first base and configured to enable light from the plurality of light-emitting devices to form monochromatic light after the light from the plurality of light-emitting devices passes through the filter layer.

An infrared window includes a substrate composed of “KRS-5” as a raw material which is mixed crystal of thallium iodide and thallium bromide and an infrared transmissive coating that covers a surface of the substrate. A raw material for the infrared transmissive coating is parylene. A thickness of the infrared transmissive coating is set to a value at which an infrared absorptance is lower than 3%. The thickness of the infrared transmissive coating is set to a value at which the infrared absorptance is lower than 3%. The thickness of the infrared transmissive coating is set to a value within a range not smaller than 20 nanometers and smaller than 50 nanometers.

An infrared window includes a substrate composed of “KRS-5” as a raw material which is mixed crystal of thallium iodide and thallium bromide and an infrared transmissive coating that covers a surface of the substrate. A raw material for the infrared transmissive coating is parylene. A thickness of the infrared transmissive coating is set to a value at which an infrared absorptance is lower than 3%. The thickness of the infrared transmissive coating is set to a value at which the infrared absorptance is lower than 3%. The thickness of the infrared transmissive coating is set to a value within a range not smaller than 20 nanometers and smaller than 50 nanometers.

An inverted nanocone structure of the present disclosure includes a first surface, a second surface spaced apart from the first surface by a predetermined distance and having a greater area than the first surface, and a body having an inverted cone shape between the first surface and the second surface, wherein at least one activated point defect center is provided in the body.