The disclosure provides in one aspect a head-up display for a vehicle. The head-up display comprises a picture generating unit, an optical system and a light-selective filter. The picture generating unit is arranged to display a picture on a screen. The optical system is arranged to receive light of the picture. The optical system comprises at least one optical element having optical power arranged to form a magnified image of the picture. The light-selective filter is transmissive to light of the picture and reflective to other light. The light-selective filter is disposed between the optical system and the screen. The light-selective filter has a first surface arranged to receive light from the optical system and a second surface arranged to receive light of the picture from the screen.

According to one embodiment, a display device includes a display panel, a holographic element which reflects light having a specific incident angle and transmits light having an incident angle different from the specific incident angle, a retardation film provided between the display panel and the holographic element, a transflective element which reflects, of the light which passed through the holographic element, first circularly polarized light, and transmits second circularly polarized light rotating in an opposite direction of the first circularly polarized light, and a lens element which has a lens effect of condensing the second circularly polarized light which passed through the transflective element.

Exemplary arrangements relate to methods for recording and reproducing holograms. A method of recording a hologram in a thresholded opto-magnetic medium (7) includes producing a collimated recording beam (1) with a pulsed laser. The intensity of the recording beam is selectively modulated by passage through a modulator (2). The recording beam is spatially shaped by passage through a shaping element (15). The shaped modulated recording beam is made convergent by passage through an aspheric lens (4). The convergent beam is deflected bidirectionally with a MEMS mirror (6) that is in operative connection with the modulator, such that multiple disposed locations on a surface of the medium are exposed to a constriction of the convergent shaped recording beam, causing a change in the medium in the locations. Reconstructing the hologram is carried out by illuminating the medium with a collimated laser beam and focusing with a lens, light from the illuminated medium onto a detection matrix. Additional methods of recording and reproducing holograms utilize alternative steps.

An optical assembly comprises a light source, a light-modulation element for modulating light from the light source, and a terminal optical element for directing modulated light from the optical assembly. Optical elements are provided to guide the light in a first path from the light source to the light-modulation element and to guide the modulated light in a second path from the light-modulation element to the terminal optical element. The first and second paths are of similar shape, for example a c-shape, and are arranged in a nested configuration.

A device for producing an edge-lit-hologram having a light source, in particular a laser light source, for generating a light beam, optical splitter for splitting the light beam generated by the light source into an object beam and a reference beam, imprinter for imprinting computer-generated information pertaining to the edge-lit-hologram to the object, optics for overlapping the object beam and the reference beam on or in a photosensitive recording medium for imprinting the edge-lit-hologram, where the optics include at least one transparent body through which the reference beam enters the photosensitive recording medium during operation of the device. The at least one transparent body shaped and disposed in the device such that the reference beam enters the body at an angle of less than 10° to the normal on the surface of the body or enters the body perpendicular to the surface of the body.

A display system for a vehicle includes a display unit mounted to the vehicle and is selectively operable in a first mode as a holographic display and in a second mode as a mirror. Holographic images may include rear view images obtained from a camera or computer generated graphics. Holographic images are displayed at a virtual image plane behind the display to reduce the operator's eyes accommodation.

The present invention discloses a method for detecting a microstructure of a functionally graded material based on digital acousto-optic holography, including the following steps: excite a sample with an ultrasonic wave; record a light wave; form a single tomographic acousto-optic hologram; perform numerical reconstruction of phase information, and perform global detection. The present invention uses an acoustic-optic modulation device to modulate a laser light source of a laser of a laser device to form two light waves of different frequencies. The two light waves each constitute a Mach-Zehnder interference system to record reflection wave information and transmission wave information of an ultrasound, and are finally combined and recorded in the same hologram to form the single tomographic acousto-optic hologram. A reflection-transmission dual-mode interference optical path is beneficial to avoiding the mutual interference of the reflection wave information and the transmission wave information, and being able to improve the integrity of information record and information redundancy by using time delay integration with point sensing and surface output to scan CCD through an image collector and cooperate with a synchronous control system to perform surface scanning and record for information of an ultrasound carrier.

Provided is a multi-image display apparatus including a light source configured to emit light, a spatial light modulator configured to provide a first image by modulating the light emitted from the light source, and an optical system configured to transmit the first image provided by the spatial light modulator to a viewer, wherein the optical system is configured such that a travelling path of the first image provided by the spatial light modulator includes a first optical path in a first direction, a second optical path in a second direction orthogonal to the first direction, and a third optical path in a third direction orthogonal to the first direction and the second direction, respectively, and wherein the optical system is configured such that the first image and a second image provided from an optical path different from the travelling path of the first image are provided to the viewer.

A holographic sight comprises a unitary optical component carrier. The unitary optical component carrier may comprise a body with a first receptacle configured to receive a laser diode, a second receptacle configured to receive a mirror, a third receptacle configured to receive a collimating optic, a fourth receptacle configured to receive a grating, and a fifth receptacle configured to receive an image hologram. A laser diode may be received within opposing walls formed by the first receptacle. A mirror may be received in, and abut one or more surfaces of the second receptacle. A collimating optic may be received in, and abut one or more surfaces of the third receptacle. A grating may be received in, and abut one or more surfaces of the fourth receptacle. A hologram image may be received in, and abut one or more surfaces of the fifth receptacle.

The present invention relates to an inline scanning holography system for a phosphor and a transmitter. According to the present invention, the inline scanning holography system includes a polarization sensitive lens that receives a linearly polarized beam and generates a first spherical wave of right-handed circular polarized light having a negative focal length and a second spherical wave of left-handed circular polarized light having a positive focal length, a polarizer that passes only a beam component in a predetermined polarization direction therethrough among components of the generated first and second spherical waves, a scanning unit for scanning a phosphor by using an interference beam generated between the first and second spherical waves passing through the polarizer, and a first photodetector that detects a fluorescent beam diverged from the phosphor. According to the present invention, a high-efficiency and high-quality optical scanning holography for a phosphor or a transmitter may be implemented.