Provided is a polarization splitting device. The polarization splitting device includes a first optical element. The first optical element comprises a light incident surface, a polarization splitting interface and a reflective interface, and the polarization splitting interface and the reflective interface are correspondingly arranged. Incident light enters the first optical element through the light incident surface, and is split into first light and second light through the polarization splitting interface; the first light is incident on the reflective optical element after being reflected by the reflective interface: and the second light exits from the first optical element after being transmitted through the polarization splitting interface.

An illuminator usable for illuminating a display panel is disclosed. The illuminator uses a pupil-replicating waveguide to expand a pair of light beams propagating in the waveguide. The light beams may be coupled at a same edge and/or at opposite edges of the waveguide, and are configured to fill each other's dark spots between out-coupled beam portions of the light beams. To improve the illumination uniformity, the two light beams may be orthogonally polarized, and the out-coupling grating strength may be spatially varied along the waveguide.

A method of operating an apparatus for laser annealing, includes reducing temporal or spatial coherency of a plurality of laser beams by beam superimposing; and reducing an electric field inner product magnitude of beams having the reduced temporal or spatial coherency by a fly eye lens array to reduce coherency, and/or by modifying a polarization state between the beams by beam superimposing.

An optical assembly includes at least one substrate that provides a first curved surface and a second surface. The optical assembly also includes a beam splitter on the first curved surface, a reflector on the second surface, and an optical retarder disposed between the beam splitter and the reflector. The optical assembly is configured to transmit the first light through the optical assembly at a first optical power. The optical assembly is also configured to transmit second light through peripheral portions of the optical assembly at a second optical power that is less than the first optical power. The first light includes light having a first polarization and wavelengths within a predetermined wavelength range. The second light includes light having wavelengths within the predetermined wavelength range and a second polarization orthogonal to the first polarization, as well as light having wavelengths outside the predetermined wavelength range.

Projection systems and components thereof are described that are well suited to miniaturization. These systems and components may use one or more of the following features: a folded optical path, as in a reflective cavity or a beamsplitter; an illumination beam that is converging at the place where it impinges upon the spatial light modulator; a beamsplitter that uses opposed prisms of substantially different sizes; a beamsplitter whose obliquely disposed partial reflector defines a first rectangular reference space, and where at least a portion of the light source or at least a portion of the projector lens is disposed within such first rectangular reference space; a system in which a ratio of areas of the first rectangular reference space and a second rectangular reference space is within a specified range, where the second rectangular reference space is just large enough to encompass the optical components of the projector; a system in which the projector lens is small compared to the spatial light modulator.

A method and an apparatus for collecting powder samples in real-time in powder bed fusion additive manufacturing may involves an ingester system for in-process collection and characterizations of powder samples. The collection may be performed periodically and uses the results of characterizations for adjustments in the powder bed fusion process. The ingester system of the present disclosure is capable of packaging powder samples collected in real-time into storage containers serving a multitude purposes of audit, process adjustments or actions.

A near-to-eye display device, includes: a display screen configured to display different images in a first time division mode, a polarization converter at a light-emitting side of the display screen and configured to convert emitted light of the different images displayed by the display screen into first circularly polarized light rays and second circularly polarized light rays in a second time division mode. Here the first circularly polarized light rays and the second circularly polarized light rays are opposite in rotation direction. The device further includes a polarization lens at a side facing away from the display screen of the polarization converter, and a focusing lens at a side facing away from the display screen of the polarization converter. The polarization lens and the focusing lens are configured to focus the first circularly polarized light rays and the second circularly polarized light rays at positions of different focal lengths.

Provided are an augmented reality optical module, including a first lens, a second lens, a third lens group, a first polarization modulation unit provided on a side of the third lens group and configured to modulate the light emitted by the image source into first circularly polarized light, an angle selection film provided on a first surface of one side of the first lens and configured to reflect light having an incidence angle greater than or equal to a first angle and transmit light having an incidence angle smaller than or equal to a second angle, and a second polarization modulation unit provided on the other side of the first lens and configured to modulate incident circularly polarized light into linearly polarized light.

A display device includes a light source, a spatial light modulator, and an optical assembly. The light source is configured to provide illumination light and the spatial light modulator is positioned to receive the illumination light. The optical assembly includes a first reflective surface with an aperture and a second reflective surface that is opposite to the first reflective surface. The optical assembly is positioned relative to the light source so that at least a first portion of the illumination light received by the optical assembly is reflected by the second reflective surface toward the first reflective surface, is reflected by the first reflective surface toward the second reflective surface, and is transmitted through the second reflective surface. A method performed by the display device is also disclosed.

An optical system of the present disclosure includes: a first optical system including a polarization conversion element aligning a polarization direction of light including color light beams with a predetermined polarization direction, and generating illumination light including the color light beams; a first polarization rotation element disposed at a first pupil position inside the first optical system, including first and second divided regions, in which the first and second divided regions have different polarization characteristics with respect to a first color light beam outputted from the polarization conversion element; a polarizer disposed between the polarization conversion element and the first polarization rotation element, and reducing light in a polarization direction other than the predetermined polarization direction included in light outputted from the polarization conversion element; and light valves each illuminated by at least the first color light beam included in the illumination light generated by the first optical system.