A projection assembly for a head-up display (HUD) includes a windshield, including an outer and inner pane joined to one another via a thermoplastic intermediate layer, and having an HUD region; and a projector directed at the HUD region. The radiation of the projector is predominantly p-polarised, and the windshield is provided with a reflective coating, which is suitable for reflecting p-polarised radiation. The reflective coating has exactly one electrically conductive layer and arranged one above and one below the electrically conductive layer are two dielectric layer sequences, each including n low-optical-refraction layers having an index of refraction less than 1.8 and (n+1) high-optical-refraction layers having an index of refraction greater than 1.8, arranged alternatingly in each case, wherein n is an integer greater than or equal to 1.

A composite pane for a head-up display, includes a first pane having a first surface and a second surface, a second pane having a first surface and a second surface, and a thermoplastic intermediate layer, which is arranged between the second surface of the first pane and the first surface (III) of the second pane, an HUD region, and a first coating for reflecting p-polarized radiation and has exactly one electrically conductive layer based on silver, wherein a second coating for reducing the total transmitted thermal radiation is provided.

An optical film includes a plurality of alternating first and second layers. The first layers have a first in-plane birefringence, the second layers have a second in-plane birefringence, and the second in-plane birefringence is less than the first in-plane birefringence and greater than 0.03. The first layers may include polyethylene terephthalate homopolymer and the second layers may include glycol-modified co(polyethylene terephthalate). The optical film has a shrinkage along a first direction of greater than 4% and a shrinkage along an orthogonal second direction of greater than 3% when heated at 150° C. for 15 minutes. A glass laminate is prepared by disposing the optical film between glass layers and laminating the optical film to the glass layers.

Optical systems including a partial reflector, a reflective polarizer, and a retarder disposed between the partial reflector and the reflective polarizer are described. The reflective polarizer is curved about two orthogonal axes and includes at least one layer that is substantially optically uniaxial at at least one location. The optical system is adapted to provide an adjustable focus.

Provided is a light source device including a plurality of light emitting points arranged in matrix within a first cross section parallel to a first direction and a second direction. When light emitting points are projected within a second cross section parallel to first direction and a third direction perpendicular to first cross section, light emitting points have equal intervals between projections adjacent to each other. When light emitting points are projected within a third cross section parallel to second and third directions, light emitting points have equal intervals between projections adjacent to each other. An interval between light emitting points adjacent to each other in a row of matrix, an interval between light emitting points adjacent to each other in a column of matrix, an angle between row and column, an angle between column and first direction, and an angle between row and second direction are appropriately set.

Strontium tetraborate can be used as an optical material. Strontium tetraborate exhibits high refractive indices, high optical damage threshold, and high microhardness. The transmission window of strontium tetraborate covers a very broad range of wavelengths, from 130 nm to 3200 nm, making the material particularly useful at VUV wavelengths. An optical component made of strontium tetraborate can be incorporated in an optical system, such as a semiconductor inspection system, a metrology system, or a lithography system. These optical components may include mirrors, lenses, lens arrays, prisms, beam splitters, windows, lamp cells or Brewster-angle optics.

A semi-transparent semi-retroreflective film and an air display device are provided. The air display device includes: a first polarizer and a second polarizer assembled with each other to form a cell; a semi-transparent semi-reflective structure and a semi-transparent semi-retroreflective film disposed between the first polarizer and the second polarizer; a first ¼ wave plate disposed at a side of the air display device adjacent to the first polarizer; and a second ¼ wave plate disposed between the semi-transparent semi-reflective structure and the semi-transparent semi-retroreflective film. The air display device is configured such that polarized light incident from the first polarizer, after being processed by an internal optical path of the air display device, exits from the second polarizer to form an air image at a side of the air display device away from the first polarizer.

In various embodiments, a pancake lens block including a shaped reflective polarizer is described. In an embodiment, the shaped reflective polarizer may include an optical element that may be configured to transmit at least a portion of light from a light source. Further, the shaped reflective polarizer may include a wire-grid polarizer that comprises (i) a bolstering substrate, (ii) a wire-grid substrate coupled to the bolstering substrate, and (iii) wire-grids disposed on the wire-grid substrate. The shaped reflective polarizer may be spaced from the optical element by a distance, which may include a cavity filled with a material (such as air or a nanovoided material).

An optoelectronic light source includes a semiconductor laser configured to produce polarized primary radiation, a converter material configured to absorb at least part of the primary radiation and convert the primary radiation into a secondary radiation of an increased wavelength, a planar multi-layered mirror located between the semiconductor laser and the converter material, the multi-layered mirror configured to transmit the primary radiation and reflect the secondary radiation, and an optical element provided between the semiconductor laser and the multi-layered mirror, wherein the optical element is configured such that the primary radiation coming from the semiconductor laser impinges on the multi-layered mirror at a Brewster angle.

The disclosure relates to an optical system, in particular for microscopy, which includes a beam splitter having a light entrance surface and a light exit surface, wherein the beam splitter absorbs. For a specified operating wavelength range of the optical system, less than 20% of electromagnetic radiation is incident on the light entrance surface. The beam splitter is arranged in the optical system such that the angles of incidence which occur during operation of the optical system at the light entrance surface and/or at the light exit surface, with reference to the respective surface normal, are at least 70°.