An optical device for exit pupil expansion (EPE) for improving a field of view (FOV) and luminance uniformity, and a display apparatus including the same are provided. The optical device includes: an input part into which a virtual image is input; and an EPE part configured to receive the virtual image from the input part, perform one-dimensional (1D) EPE and two-dimensional (2D) EPE to combine the virtual image with an external real image, and output the combined image.

An optical waveguide system and an electronic device are disclosed. The system comprises: a waveguide; an input coupler coupling a light into the waveguide; and an output coupler, wherein the input coupler includes a right portion and a left portion, wherein the right portion includes stacked first and second polarization volume gratings, the left portion includes stacked third and fourth polarization volume gratings. The first and fourth polarization volume gratings are polarization volume gratings optimized for a right-hand-side field of view of the light, and the third and second polarization volume gratings are polarization volume gratings optimized for a lefthand-side field of view of the light.

A security element for manufacturing value documents has a structure including first and second motifs which change their appearance when the security element is tilted over a tilting angle range. The structure has first micro-elements, which are arranged with a first pattern and a first motif, and second micro-elements, which are arranged with a second pattern and a second motif. The first and second patterns are nested within each other on an areal region of the security element and have different visual appearances according to the tilting of the securing element.

A static-image augmented privacy display, mode-switchable privacy display system, and method provide a private image to a first view zone and a static image to a second view zone. The static-image augmented privacy display includes a privacy backlight configured to provide directional emitted light to the first view zone and an array of light valves configured to modulate the directional emitted light to provide a private image within the first view zone. The static-image augmented privacy display also includes a static display layer configured to provide a static image in a second view zone. The mode-switchable privacy display includes a broad-angle backlight configured to provide broad-angle emitted light to both a first view zone and a second view zone during a shared mode, a shared image being provided by modulation of the broad-angle emitted light using the light valve array.

A diffraction optical element is disclosed. The diffraction optical element includes a substrate and multiple grating units. The grating units are disposed above the substrate. The grating units diffract incident light to generate diffracted light being passing through the substrate. A refractive index of the substrate is substantially below 1.45.

A method for forming an optical device and an optical device, wherein upon illumination, exhibits diffractive images dependent upon viewing angle, the device having a diffractive structure including grating regions, each region corresponding to a component of a respective diffractive image, wherein: each region of the diffractive structure includes grating elements along a first direction having a principal orientation component within the device plane that is substantially orthogonal to the first direction; wherein, the grating elements within each grating region have a constant pitch and the same orientation wherein each grating region, upon illumination, exhibits a diffractive color wherein the corresponding diffractive image is exhibited; wherein, the diffractive structure includes first and second grating regions elongated along a common first direction, the regions being adjacent along the first direction, and wherein the pitch and/or orientation of the grating elements of the first and second grating regions are different.

A security device includes a diffractive structure, including grating elements and having a first area, the grating elements within a region have a constant pitch or spacing; the first area regions pitches or spacings increase from one region to the next between a first region having a grating element pitch or spacing of less than or equal to 0.6 microns and an end region having a grating element pitch or spacing of greater than or equal to 5 microns; upon illumination and viewing along a first viewing direction substantially orthogonal to the first axis, the device exhibits a first optical effect in that at least one region exhibits a diffractive colour; each region has at least first and second sub-regions having different grating element orientations within the plane of the device such that the first optical effect is exhibited at more than one angle of tilt about the second axis.

Disclosed is a diffractive optical element includes a substrate (BS) having a first surface and a second surface opposite the first surface, being transparent to light in at least one spectral range and having, in the spectral range, a refractive index that is greater than that of water, at least one metasurface able to diffract light radiation of wavelength λ within the spectral range, incident with an angle of incidence, according to a diffracted radiation, so that the diffracted radiation propagates in the substrate and reaches the second surface of the substrate at a diffracted angle θ.sub.d that is greater than or equal to a limit angle (θ.sub.c) of total internal reflection between the substrate and water, the metasurface being designed to have, for the angle of incidence, a transmission with a 0 order of diffraction below 5% and a transmission of the diffracted radiation corresponding to a −1 or +1 order of diffraction above 50%.

A subwavelength grating displaying a colored image exhibiting a color corresponding to a grating period of a subwavelength grating in reflection directions including a specular reflection direction. A relief surface displaying a reflection image in monochromatic reflected light in reflection directions including a direction different from the specular reflection direction. An optical element has a first state in which neither a colored image nor a reflection image is displayed, a second state in which the colored image is mainly displayed, and a third state in which the reflection image is mainly displayed. A plane in which the optical element is disposed and a plane including a line of sight of an observer form an observation angle therebetween. The optical element is observed in any of the first, second and third states according to the observation angle.

There are provided a solid-state imaging device capable of improving quantum efficiency while suppressing occurrence of color mixture, and a method of manufacturing such a solid-state imaging device. According to the present disclosure, a solid-state imaging device (100, 100a, 100b, 100c) is provided. The solid-state imaging device (100, 100a, 100b, 100c) includes a first region (4, 4a, 4b) and a second region (5, 5a) in a light receiving surface of an imaging pixel (1, 1a, 1b, 1c). The first region (4, 4a, 4b) is provided with unevenness. The second region (5, 5a) is provided with unevenness having a pitch narrower than that of the unevenness in the first region (4, 4a, 4b).