An optical composite film includes a reflection grating film layer, an optically-uniaxial optical film layer, and a substrate layer. The optically-uniaxial optical film layer includes a plate-shaped portion and a plurality of refraction portions, where the plate-shaped portion is disposed on the reflection grating film layer, the plurality of refraction portions is disposed on a side of the plate-shaped portion away from the reflection grating film layer, the plurality of refraction portions is selected from one type of camber columns and quadrangular prisms, and an extraordinary light refractive index of the optically-uniaxial optical film layer is less than an ordinary light refractive index of the optically-uniaxial optical film layer; and the substrate layer is stacked on a side of the plate-shaped portion close to the refraction portion.

A rotational geometric phase hologram has geometric phase optical elements (GPOEs) serially cascaded along a common optical axis to form a GPOE cascade used for receiving a linearly-polarized light beam and generating output light beams at an exit surface of the last GPOE. Interference occurred in the output light beams creates a polarization interference pattern on the exit surface. A photoalignment substrate, when positioned in close proximity to the exit surface, records the pattern. Advantageously, each GPOE is rotatable about the common optical axis. Respective rotation angles of the GPOEs are determined according to a spatially-varying linear polarization orientation distribution selected to be generated for the polarization interference pattern. Particularly, the respective rotation angles are reconfigurable to provide the periodicity required for the spatially-varying linear polarization orientation distribution over a range of allowed periodicities while keeping the periodicity of spatially-varying optic axis orientation distribution of each GPOE to be fixed.

This invention is to provide a spectroscope that can improve resolution and reduce loss of light intensity and/or distortion of a wave front while enabling detection of the optical spectrum for each of a plurality of polarization components in incident light. The spectroscope is a spectroscope that comprises a first diffraction grating 51 to which at least a transmitted light or a reflected light from an object to be measured enters, which diffracts a first polarization component of the incident light and which transmits a second polarization component that is different from the first polarization component of the incident light without diffraction, and a first light-receiving element 55 that receives a spectrum of the light diffracted by the first diffraction grating 51.

The present disclosure relates to a waveguide-based augmented reality display apparatus, which includes an image source alternately displaying an image at a preset frequency and correspondingly generates a first polarized light and a second polarized light; a single waveguide being spaced from the image source; a first in-coupling device, arranged on one side of the waveguide and configured to couple the first polarized light into the waveguide; a second in-coupling device, arranged on the other side of the waveguide and configured to couple the second polarized light into the waveguide; an out-coupling device, arranged on the waveguide and configured to alternately couple out a first sub-image and a second sub-image in a preset area. The first and second sub-images are alternately displayed, and are fused and superimposed in human eyes due to a persistence of vision, thereby increasing a field of view and an image resolution.

An object of the present invention is to provide a light irradiation device which is thin and is capable of projecting an optical pattern, and a sensor which uses the light irradiation device. The object is achieved by a light irradiation device including a light emitting element which includes a plurality of light emitting units in a plane; and a liquid crystal optical element, in which the liquid crystal optical element has an optically anisotropic layer formed using a liquid crystal composition containing a liquid crystal compound, the optically anisotropic layer has a liquid crystal alignment pattern in which orientation of an optical axis derived from the liquid crystal compound continuously changes rotationally along at least one in-plane direction and has regions with different lengths of periods in a case where a length over which the orientation of the optical axis derived from the liquid crystal compound rotates by 180 in the plane is denoted by a single period.

A first layer of anisotropic material extends along a first plane and includes anisotropic components being parallel to a second plane non-parallel and non-perpendicular to the first plane. The anisotropic components are arranged in cycloidal or helical patterns. The cycloidal or helical patterns define one or more Bragg planes that are non-parallel and non-perpendicular to the first plane and either substantially parallel or substantially perpendicular to the second plane.

An optical device includes a stack of multiple grating structures, each of which includes a plurality of sublayers of liquid crystal material. Each sublayer of liquid crystal material includes laterally extending repeating units, each formed of a plurality of liquid crystal molecules. The repeating units of the liquid crystal layers are lateral offset from one another, and defined a tilt angle. The grating structures forming the stack of grating structure have tilt angles of different magnitudes. The grating structures may be configured to redirect light of visible or infrared wavelengths. Advantageously, the different tilt angles of the stack of grating structures allows for highly efficient diffraction of light incident on the grating structures at a wide range of incident angles.

An optical system includes a substrate and a polarization volume hologram (PVH) composite film formed over the substrate. The PVH composite film includes a first PVH layer formed over the substrate and having a helix twist of a first handedness, and a second PVH layer coupled to the first PVH layer and having a helix twist of a second handedness orthogonal to the first handedness. The first PVH layer is configured to reflect and converge circularly polarized light having the first handedness. The second PVH layer is configured to reflect and converge circularly polarized light having the second handedness.

A diffraction grating may include a substrate. The diffraction grating may include an etch stop layer to prevent etching of the substrate. The etch stop layer may be deposited on the substrate. The diffraction grating may include a marker layer to indicate an etch end-point associated with etching of a dielectric layer. The marker layer may be deposited on a portion of the etch stop layer. The diffraction grating may include the dielectric layer to form a grating layer after being etched. The dielectric layer may be deposited on at least the marker layer.

An optical device includes a stack of multiple grating structures, each of which includes a plurality of sublayers of liquid crystal material. Each sublayer of liquid crystal material includes laterally extending repeating units, each formed of a plurality of liquid crystal molecules. The repeating units of the liquid crystal layers are lateral offset from one another, and defined a tilt angle. The grating structures forming the stack of grating structure have tilt angles of different magnitudes. The grating structures may be configured to redirect light of visible or infrared wavelengths. Advantageously, the different tilt angles of the stack of grating structures allows for highly efficient diffraction of light incident on the grating structures at a wide range of incident angles.