Many embodiments in accordance with the invention are directed towards waveguides implementing birefringence control. In some embodiments, the waveguide includes a birefringent grating layer and a birefringence control layer. In further embodiments, the birefringence control layer is compact and efficient. Such structures can be utilized for various applications, including but not limited to: compensating for polarization related losses in holographic waveguides; providing three-dimensional LC director alignment in waveguides based on Bragg gratings; and spatially varying angular/spectral bandwidth for homogenizing the output from a waveguide. In some embodiments, a polarization-maintaining, wide-angle, and high-reflection waveguide cladding with polarization compensation is implemented for grating birefringence. In several embodiments, a thin polarization control layer is implemented for providing either quarter wave or half wave retardation.

Many embodiments in accordance with the invention are directed towards waveguides implementing birefringence control. In some embodiments, the waveguide includes a birefringent grating layer and a birefringence control layer. In further embodiments, the birefringence control layer is compact and efficient. Such structures can be utilized for various applications, including but not limited to: compensating for polarization related losses in holographic waveguides; providing three-dimensional LC director alignment in waveguides based on Bragg gratings; and spatially varying angular/spectral bandwidth for homogenizing the output from a waveguide. In some embodiments, a polarization-maintaining, wide-angle, and high-reflection waveguide cladding with polarization compensation is implemented for grating birefringence. In several embodiments, a thin polarization control layer is implemented for providing either quarter wave or half wave retardation.

A spectacle-type terminal device comprises: a lens; a front body portion configured to allow parts to be mounted thereon and formed to support and secure the lens; and an optical engine disposed in a region within the front body portion and generating an image light that serves as an image source of a virtual image. There may be formed a holographic optical element (HOE), which is formed in at least one area of photopolymers formed on an inner surface or inside area of the lens, and is configured to display a virtual image corresponding to the image light by diffracting the image light.

Systems and methods for reducing glare from a heads-up display (HUD). Internal and external antireflective coatings may be provided on interior and outer surfaces of glass layers surrounding a holographic polymer layer. A substrate guided hologram may be integrated into a HUD to diffract and direct external radiation to the edge of a HUD. An arrangement for forming a substrate guided hologram includes an array of reflectors and a shaped glass block. Antireflective coated glass layers may be index-matched to opposite sides of a holographic polymer film prior to recording a reflection hologram. An inactive playback beam may be used to monitor the diffraction efficiency of a reflection hologram and of a spurious transmission hologram with the recording of the reflection hologram to maximize the difference between the diffraction efficiencies of useful reflection hologram and spurious transmission hologram.

An optical coupler includes a plurality of volume gratings in a substrate. The gratings include an array of fringes extending along length and thickness dimensions of the substrate. A difference between a refractive index of the fringes and a refractive index of the substrate depends on a depth coordinate along the thickness dimension of the substrate. A dependence of the difference on the depth coordinate has a bell-shaped function which suppresses ghost image formation due to optical crosstalk between gratings of neighboring spatial pitches.

A head-up display for a vehicle having a window. The head-up display comprises a picture generating unit and a projection engine. The picture generating unit is arranged to output pictures. Each picture comprises a first picture component and a second picture component. The projection engine is arranged to receive the pictures output by the picture generating unit and project the pictures onto the window of the vehicle in order to form a first virtual image of the first picture component at a first virtual image distance and a second virtual image of the second picture component at a second virtual image distance. Light of the first picture component is polarised in a first polarisation direction and light of the second picture component is polarised in a second polarisation direction perpendicular to the first polarisation direction. The projection engine comprises an optical element having first optical power in the first polarisation direction and second optical power in the second polarisation direction such that the first virtual image distance is not equal to the second virtual image distance. The projection engine is further arranged such that the first virtual image and second virtual image at least partially overlap.

A method of manufacturing a holographic optical element, including: irradiating a first surface of a photosensitive substrate with a first layer, and irradiating a second surface of the photosensitive substrate with a second laser. The light emitted by the first laser is spread in an irradiation direction and the light emitted by the second laser is collected in the irradiation direction to form a plurality of groups and a plurality of overlapping angles formed by a progress direction of the light emitted by the first laser and the progress direction of the light emitted by the second laser at a predetermined location of a photosensitive area, and each of the plurality of the overlapping angles are different from each other. A display device including the holographic optical element measured using this method.

An optical reflective device for pupil equalization including at least one or more grating structures within a grating medium is disclosed. The grating structures may have reflective axes that need not be constrained to surface normal. The grating structures are configured to reflect light about substantially constant reflective axes across a relatively wide range of wavelengths. The optical reflective device may reflect light towards a specific location, such as an exit pupil or eye box. Each grating structure within the device may be configured to reflect light of a particular wavelength at a plurality of incidence angles.

Provided is a light guide plate for image display, whereby clear images can be displayed even when a resin base is used, wherein the light guide plate for image display (1004) has a first resin base (1001) and a hologram layer (1002), and wherein the first resin base (1001) has an MC value of 0.120 or less obtained by evaluation using shadow contrast.

A holographic optical element, a method for manufacturing the same and an apparatus for producing the same are provided. More particularly, the holographic optical element is capable of enhancing the brightness of an augmented image. In one example, the holographic optical element includes a plurality of optical elements combined together and has interference patterns recorded on the plurality of optical elements, respectively. The interference patterns have the same pitch and different inclination angles