In an electro-optical device, a first polarizing element, a first phase difference element, a transmissive liquid crystal panel, a second phase difference element, and a second polarizing element are sequentially arranged. Here, when a phase difference of the first phase difference element and the second phase difference element is λ/4, an influence of orientation disorder of liquid crystal molecules can be alleviated, but a contrast ratio is reduced. Therefore, when a wavelength of incident light is λ, a phase difference R of the first phase difference element and the second phase difference element satisfies the following condition that 0<R<λ/4, preferably λ/12<R<λ/6. For example, it is assumed that the phase difference R is λ/8.

Optical film stacks are described. More particularly, optical film stacks including a half-wave retardation layer are described. Achromatic half-wave retardation layers, including achromatic half-wave layers formed from a quarter-wave and a three-quarters-wave retardation layer, are described. Film stacks including reflective polarizers tuned to reduce wavelength dispersion of the half-wave retardation layer are also described.

An optical device for illuminating one or more portions of a spatial light modulator includes a waveguide, an array of tunable retarders, and a polarization selective optical element. A respective tunable retarder is optically coupled to receive light from the waveguide. The respective tunable retarder has a first state, which causes the respective tunable retarder to direct light having a first polarization in a first direction, and a second state, which causes the respective tunable retarder to direct light having a second polarization distinct from the first polarization in the first direction. The polarization selective optical element is located adjacent to the array of tunable retarders so that the light having the first polarization propagates from the polarization selective optical element in a second direction and the light having the second polarization propagates from the polarization selective optical element in a third direction distinct from the second direction.

A vehicular rearview assembly includes an electro-optic element. A first substrate defines a first element surface and a second element surface. A first polarizer is coupled to the second element surface. A second substrate is spaced away from the first substrate and defines a third element surface and a fourth element surface. An electro-optic material is positioned between the first and second substrates. A second polarizer is coupled to the second substrate. A display is configured to emit light having a first polarization toward the second polarizer.

The present disclosure relates generally to techniques for improving the performance and efficiency of optical systems, such as optical systems for using head-mounted display system. The optical systems of the present disclosure may include polarized catadioptric optics, or “pancake optics,” which utilize a wire grid polarizer as a reflective polarizer. Wire grid polarizers may not perform uniformly over wavelength or over varying angles of incidence. To improve performance, a spatially varying polarizer is provided in the optical system that operates to provide polarization compensation for the wire grid polarizer so that the wire grid polarizer performs more uniformly over wavelength and/or over incidence angles (e.g., on-axis and off-axis). The spatially varying polarizer may be formed of a liquid crystal material, such as a multi-twist retarder.

Optical film stacks are described. More particularly, optical film stacks including a half-wave retardation layer are described. Achromatic half-wave retardation layers, including achromatic half-wave layers formed from a quarter-wave and a three-quarters-wave retardation layer, are described. Film stacks including reflective polarizers tuned to reduce wavelength dispersion of the half-wave retardation layer are also described.

Systems and methods are disclosed for selectively allowing or preventing output of laser pulses. In some embodiments, a laser system comprises a shutter and a shutter motor. The shutter motor is configured to move the shutter in an alternating manner between a first position in which output of laser electromagnetic radiation is allowed a second position in which output of laser electromagnetic radiation is prevented.

A liquid crystal display panel and a liquid crystal display device are disclosed. The liquid crystal display panel includes a display module and a packaging cover plate disposed on a light-emitting side of the display module. The packaging cover plate includes a cover plate body and a first polarizer, wherein the first polarizer is disposed on a side of the cover plate body adjacent to the display module and/or on a side of the cover plate body away from the display module.

A phase delay device, its preparation method and a display equipment are provided. The phase delay device includes linear polarization layer, alignment layer and liquid crystal layer. The linear polarization layer is configured to convert received light into a linear polarization light; the alignment layer is configured to align liquid crystals of a first subpart of the liquid crystal layer based on a preset alignment angle; the liquid crystal layer is located at a side of the alignment layer away from the linear polarization layer, and includes a first subpart adjacent to the alignment layer, a second subpart having a spiral structure with a preset spiral angle and a third subpart; a liquid crystal alignment angle of the third subpart is determined based on the preset alignment angle and the preset spiral angle; birefringence of the liquid crystal layer does not decrease with an increase of visible light wavelength.

A display assembly includes a display panel and at least one optical film group each disposed on a display surface. Each optical film group includes a quarter-wave plate, a reflective polarizer and an absorbing polarizer. The reflective polarizer includes a reflective portion capable of allowing light with a polarization direction parallel to a polarization axis of the reflective polarizer to pass through and reflecting light with a polarization direction perpendicular to the polarization axis. An orthographic projection of an effective light-emitting area of at least one sub-pixel is substantially within an orthographic projection of the reflective portion. The absorbing polarizer is capable of allowing light with a polarization direction parallel to a polarization axis of the absorbing polarizer to pass through and absorbing light with a polarization direction perpendicular to the polarization axis. The polarization axis of the reflective polarizer is parallel to the polarization axis of the absorbing polarizer.