Embodiments of the disclosure provide a display panel and a display device. The display panel includes a substrate, a plurality of light emitting elements and at least one transmissive-reflective module, where the light emitting elements are arranged on the substrate; each of the light emitting elements includes a first electrode, a light emitting functional layer and a second electrode arranged along a direction vertical to the substrate and away from the substrate; the at least one transmissive-reflective module is arranged on a side, close to the substrate, of the first electrode of at least one of the light emitting elements, and/or on a side, away from the substrate, of the second electrode of at least one of the light emitting elements; the transmissive-reflective module is configured to switch between a transmissive state and a reflective state.

Implementations are described of an eyepiece for a head wearable display. The eyepiece includes a curved lightguide for guiding display light via total internal reflection between a peripherally-located input surface and a viewing region and an output coupler disposed across the viewing region to redirect the display light towards an eyeward direction for output from the curved light guide. The output coupler has an optical axis and has a set of reflective surfaces that includes at least two individual reflective surfaces to reflect incident display light toward the eyeward direction in at least two different directions relative to the optical axis of the output coupler. Other embodiments are disclosed and claimed.

A device is provided. The device includes a reflective polarizer configured to selectively reflect or transmit a polarized light based on a polarization of the polarized light. The device also includes a display element disposed at a first side of the reflective polarizer, and configured to output a first image light representing a virtual image. The device also includes a polarization switch disposed between the display element and the reflective polarizer, and configured to switch or maintain a polarization of the first image light. The device further includes an active dimming device disposed at a second side of the reflective polarizer, and configured to provide an adjustable transmittance of an input light.

Disclosed herein are techniques for improving the light collection efficiency in coaxial LiDAR systems. A coaxial LiDAR system includes a photodetector, a first polarization beam splitter configured to receive a returned light beam including a first linear polarization component and a second linear polarization component and direct the different linear polarization components to different respective directions, a polarization beam combiner configured to transmit the first linear polarization component from the first polarization beam splitter to the photodetector, a non-reciprocal polarization rotator configured to transmit the second linear polarization component from the first polarization beam splitter, and a second polarization beam splitter configured to reflect the second linear polarization component from the non-reciprocal polarization rotator towards the polarization beam combiner. The polarization beam combiner is further configured to reflect the second linear polarization component from the second polarization beam splitter to the photodetector.

Liquid crystal devices are described that maintain performance of polarization/amplitude modulation under high irradiance conditions. Configurations that isolate polarizing elements under high thermal load are discussed which allow other elements, such as glass, which may be sensitive to stress birefringence to remain near optimum thermal conditions.

Apparatus for generating THz (teraftertz) radiation, the apparatus comprising: a substrate; a planar array of subwave-length antennas formed on the substrate having rotational symmetry, Cn, of order “n” greater than or equal to 3 and rotational symmetry cycle 2π/η, which are excitable by near infrared (NIR)_pump radiation to radiate THz radiation having wavelengths that are substantially larger than characteristic dimensions of the subwavelength antenna; wherein the array comprises a plurality of sections each comprising plurality of subwavelength antennas exhibiting a spatial pattern different from that of an adjacent section of the plurality of sections.

An eyewear device includes a lightguide having a world-side surface and an eye-side surface, a display oriented to emit light toward the lightguide, and a beam steering element that includes a first polarization grating positioned along an optical path between the display. The first polarization grating diffracts light emitted by the display into orders having different polarizations and the orders are selectively conveyed into different eyeboxes. The eyewear device also includes a frame that supports the lightguide, the display, and the first polarization grating. In some cases, the different polarizations include a right circular polarization or a left circular polarization and the beam steering element includes a polarization dependent filter that filters right circularly polarized light in a first state and left circularly polarized light in a second state.

According to an aspect of an embodiment, operations may include receiving a light wave and generating a pumping wave by performing polarization modulation on the light wave based on a bit stream. The pumping wave may include a first polarization component having a first polarization and a second polarization component having a second polarization and having a same wavelength as the first polarization component. The operations may also include emitting the pumping wave in an optical medium such that the pumping wave amplifies an optical signal propagating within the optical medium.

A method and an apparatus of a powder bed fusion additive manufacturing system that enables a quick change in the optical beam delivery size and intensity across locations of a print surface for different powdered materials while ensuring high availability of the system. A dynamic optical assembly containing a set of lens assemblies of different magnification ratios and a mechanical assembly may change the magnification ratios as needed. The dynamic optical assembly may include a transitional and rotational position control of the optics to minimize variations of the optical beam sizes across the print surface.

A light detection and ranging (LIDAR) pixel includes a splitter, a grating coupler, and a phase shifter. The grating coupler is configured to emit a transmit beam that is based on a combination of a first portion of light and a second portion of light received from a laser. One or more first interconnects and one or more second interconnects couple the splitter to the grating coupler. The phase shifter is coupled to the one or more first interconnects and configured to vary a phase of the first portion of the light relative to a phase of the second portion of the light.