A light projection apparatus is provided comprising: a source of light; a switchable grating on a first substrate; and a diffractive optical element. Light is diffracted at least once by the switchable grating and is diffracted at least once by the DOE.

A method for recording a plurality of scatter volume holograms in a photopolymeric recording medium, the method including at least the following steps providing a first laser light source, providing a photopolymeric recording medium including a substrate and a photoactive layer, wherein the photopolymeric recording medium has an index modulation n of at least 0.04 and a thickness d of the photoactive layer of at least 25 m, and irradiating the photopolymeric recording medium with the first laser light beam generated by the first laser light source with a minimum irradiation energy dosage of 3*D.sub.i, D.sub.i being the inhibition dosage of the photoactive layer.

An interactive 3D display apparatus and method are provided. The interactive 3D display apparatus includes a hand sensing module configured to acquire a hand image by detecting a hand of a user and a user interaction module configured to generate a virtual object adjustment parameter by analyzing user-intended information about the hand based on the hand image acquired by the hand sensing module and comparing an analysis result with predefined user scenarios, an image rendering module configured to set a scene according to the generated virtual object adjustment parameter, generate image data by rendering the set scene, and convert the generated image data into display data, and a 3D display configured to display a 3D image including a virtual object in which a change intended by the user has been reflected according to the display data.

A head worn imaging system includes a light source configured to generate a light beam. The system also includes a light guiding optical element having a thickness between 0.1 and 1.5 mm and configured to propagate at least a portion of the light beam by total internal reflection. The system further includes an entry portion and an exit portion of the light guiding optical element configured to selectively allow light addressing the exit portion to exit the light guiding optical element based on the angle of incidence of the light, the radius of curvature of the light and/or the wavelength of the light.

Systems, devices, and methods for expanding the eyebox of a wearable heads-up display are described. A light guide with an expanded eyebox includes a light guide material, an in-coupler, an outcoupler, and a gradient refractive index (GRIN) material. The in-coupler and the out-coupler may comprise a GRIN material. An eyeglass lens with expanded eyebox includes a light guide with expanded eyebox. A wearable heads-up display includes an eyeglass lens including a light guide with an expanded eyebox.

A backlight module, a holographic display device and a holographic display method thereof are provided. The backlight module includes a semi-transparent layer and a reflective layer which are disposed opposite to each other, a light source, and a deflectable optical device. The light source is configured to emit a light beam, the deflectable optical device is configured to deflect a propagation direction of the light beam emitted from the light source and make the reflected light beam enter between the semi-transparent layer and the reflective layer in an angle, and is deflectable to change the angle.

A holographic image film, and a holographic image recording method and reconstruction method are provided. The holographic image recording method includes a preparation step, an irradiation step and a recording step. The preparation step includes stacking a holographic negative film on a transparent substrate. The irradiation step includes emitting object light and reference light. The reference light is emitted into the transparent substrate and undergoes multiple times of total reflections in a thickness of the transparent substrate to form total internal reflected light. The recording step includes generating a holographic image interference line by a mutual interference between the total internal reflected light and the object light, and recording the holographic image interference line on the holographic negative film in a photosensitive manner.

A backlight unit for a binocular-holographic display device and a holographic display device including the same are provided. The backlight unit includes a light source unit which outputs light, a first beam expansion unit which expands, in a first direction, the light output from the light source unit, a second beam expansion unit which expands, in a second direction perpendicular to the first direction, the light output from the first beam expansion unit, and a beam deflection unit which diffracts light incident on the first beam expansion unit. The holographic display device includes the backlight unit, a field lens, and a spatial light modulator.

A head worn imaging system includes a light source configured to generate a light beam. The system also includes a light guiding optical element having a thickness between 0.1 and 1.5 mm and configured to propagate at least a portion of the light beam by total internal reflection. The system further includes an entry portion and an exit portion of the light guiding optical element configured to selectively allow light addressing the exit portion to exit the light guiding optical element based on the angle of incidence of the light, the radius of curvature of the light and/or the wavelength of the light.

Multiple pairs of substrate-guided wave-based holograms (SGWHs) are laminated to a common thin substrate to form a transparent substrate-guided wave-based holographic CHMSL (SGWHC) that diffracts playback LED illumination over a wide angular range. This device is made pursuant to a technique that includes the steps of recording a first set of SGWHs with one setup, that upon playback, will couple and guide the diffracted light inside the substrate, and a second set of SGWHs recorded with another setup, that will diffract and couple the guided light out.