There is disclosed herein a waveguide comprising an optical slab and an optical wedge. The optical slab has a first refractive index, n.sub.1>1. The optical slab comprises: a pair of opposing surfaces and an input port. The pair of opposing surfaces are arranged in a parallel configuration. The input port is arranged to receive light into the optical slab at an angle such that the light is guided between the first and second opposing surfaces by a series of internal reflections. The optical wedge has a second refractive index, n.sub.2, wherein 1<n.sub.2<n.sub.1. The optical wedge comprises a pair of opposing surfaces arranged in a wedge configuration. A first surface of the optical wedge abuts the second surface of the optical slab to form an interface that allows partial transmission of light guided by the optical slab into the optical wedge at a plurality of points along the interface such that the light is divided a plurality of times. The angle of the wedge allows light received at the interface to escape through the second surface of the optical wedge such that the exit pupil of the waveguide is expanded by the plurality of divisions of the light.

Methods, devices and systems for improved fabrication and measurement of holographic elements are described. One example method includes directing a reference and an object beam toward a holographic material for formation of a diffraction grating in the holographic material, and blocking one of the reference or the object beams to prevent the beam from reaching the holographic material for at least a portion of time during which the diffraction grating is being formed. During the blockage of the beam, a power level of a diffracted beam associated with the reference or the object beam that is not being blocked is measured. Based on the measured power level, it is then determined whether a particular diffraction grating efficiency is reached. The described techniques enable real-time measurement of diffraction grating efficiency as the grating is being formed and enable improved fabrication of holographic elements hat must meet precise diffraction grating efficiency requirements.

The present invention relates to a system and method for digital holographic microscopy. According to an aspect of the invention there is provided an off-axis digital holographic microscope comprising: a light emitter configured to provide a divergent light beam; a sensor position to receive light from the light emitter in a first path and a second path, and thereby to detect a holographic image; a reflector positioned partially in the divergent light beam so that light that encounters the reflector extends towards the sensor in the first path, and light that does not encounter the reflector extends towards the sensor in the second path; and a support structure configured to support a sample in the first path or the second path.

An apparatus for manufacturing a radial or azimuthal polarization conversion component includes a reflector having a truncated cone shape. The reflector has a top portion, a bottom portion, and a circumferential portion connected between the top portion and the bottom portion. When a light beam is incident vertically from above, a part of the light beam vertically passes through the top portion to the bottom portion, a part of the light beam enters the circumferential portion at an incident angle and forms a reflected light beam to enter the bottom portion at an incident angle, the reflected light enters the holographic recording material at a refraction angle to generate an exposure range;

A method for manufacturing a radial or azimuthal polarization conversion component comprises the steps of: placing a holographic recording material between two right-angle prisms, wherein the holographic recording material is divided into at least four sector-shaped areas and is partially shielded, and only one of the sector-shaped areas is exposed each time; allowing a recording light to pass through the right-angle prisms and the exposed sector-shaped area of the holographic recording material and to interfere with a reflected object light on the holographic recording material; rotating the holographic recording material to expose the other sector-shaped areas one by one to be constructed for manufacturing volume holograms with diffraction angles of 48.19 degrees, 60 degrees or about 85 degrees.

Provided is a waveguide having a light diffraction unit that diffracts incident light by a multiplex-recorded hologram, in which, in the light diffraction unit, a plurality of holograms having different angles with respect to an incident surface of the waveguide are formed, and when certain parallel light beams are incident, different wavelengths are diffracted by the plurality of holograms.

A prism layer has an uneven surface that includes at least one display region. An interface layer is adjacent to the uneven surface. The interface layer has a difference in refractive index from the prism layer such that a refractive index of a side of an interface between the uneven surface and the interface layer at which the prism layer is located is higher than a refractive index of a side of the interface at which the light interference layer is located. The display region includes inclination elements. The inclination elements adjacent to each other in an array direction contact each other in a plan view facing a plane along which the prism layer expands. The inclination elements include first inclination elements among which the inclination angle increases by the even angles along the array direction.

A holographic projector having an optical path is described. The holographic projector comprises a first spatial light modulator arranged to display a first hologram, and a first light source. The first light source is arranged to illuminate the first spatial light modulator with light of a first wavelength such that a first holographic reconstruction corresponding to the first hologram is formed on a replay plane. The holographic projector further comprises a continuous block of transparent material. At least part of the optical path is formed through the continuous block of transparent material. The transparent material has a refractive index greater than air.

A display device includes a light source, a waveguide element, a liquid crystal coupler, a first holographic optical element and a second holographic optical element. The light source is configured to emit light. The waveguide element is located above the light source. The liquid crystal coupler is located between the waveguide element and the light source. The first holographic optical element is located on a top surface of the waveguide element, in which the liquid crystal coupler is configured to change an incident angle that the light emits to the first holographic optical element. The second holographic optical element is located on the top surface of the waveguide element, and there is a first distance in a horizontal direction between the first holographic optical element and the second holographic optical element, in which the second holographic optical element is configured to diffract the light to the waveguide element below.

To reduce an influence of stray light and stably record/reproduce high-quality data in holographic recording/reproduction. A holographic memory device includes an optical system that guides a reference beam to an optical information recording medium at a desired angle of incidence, a control part that controls the angle of incidence of the reference beam generated in the optical system, and a lens part that images the reference beam in a desired position of the optical information recording medium. Further, at least a first light beam at a first angle and a second light beam at a second angle different from the first angle are output from the optical element, and the optical element is provided so that the first light beam may propagate within an effective diameter of the lens part and the second light beam may propagate to an outside of the effective diameter of the lens part.