A method to form a three-dimensional photonic crystal template with a gradient structure involves irradiating a photoresist composition of a thickness of at least 15 μm from at least four laser beams to yield a periodic patterned with a percolating matrix of mass in constructive volumes of a cured photoresist composition and destructive volumes of voids free of condensed matter where the proportion of constructive volume displays a gradient from the irradiated surface to the substrate after development. For a given light intensity, photoinitiator concentration in the photoresist composition, and a given thickness, by irradiating for a relatively short period, a three-dimensional photonic crystal template displaying a gradient having greater constructive volume proximal the air interface forms and a relatively long irradiation period results in a gradient having greater constructive volume proximal the substrate.

A method for adjusting the apparent brightness of a computer-generated hologram display is disclosed. The method comprises: receiving source data representative of a scene to be displayed as a hologram; determining hologram data to display a computer-generated hologram representing the scene; determining a scene energy based on the source data, the scene energy being quantised using a scale which is non-linear and which has a closer spacing between values in a mid-section of the scale than between values towards a minimum and a maximum of the scale; associating the scene energy with the hologram data; controlling a holographic display according to the hologram data and simultaneously controlling an output power of an illumination source of the holographic display according to the scene energy. A holographic display apparatus implementing the method is also disclosed.

A method for generating video holograms in real time for a holographic playback device comprising at least one light modulator means, into which a scene divided into object points is encoded as an entire hologram and can be seen as a reconstruction from a visibility region, which is located within a periodicity interval of the reconstruction of the video hologram, the visibility region defining a subhologram together with each object point of the scene to be reconstructed, and the entire hologram being generated from a superposition of contributions of subholograms, is characterized in that for each object point the contributions of the subholograms in the entire reconstruction of the scene can be determined from at least one look-up table.

Projection displays include a highlight projector and a main projector. Highlights projected by the highlight projector boost luminance in highlight areas of a base image projected by the main projector. Various highlight projectors including steerable beams, holographic projectors and spatial light modulators are described.

A spatial modulator is provided on a plane conjugate to a sample plane on which a sample is to be placed. The spatial modulator spatially modulates illumination light irradiated to the sample 2 or object light that has passed through or that has been reflected by the sample. A dark-field optical system removes the non-scattered light component of the first object light affected by the spatial light modulator so as to generate second object light. An image sensor records a hologram based on the second object light. A calculation processing apparatus combines complex amplitude information based on the modulation pattern supplied to the spatial light modulator and complex amplitude information based on the hologram with respect to the second object light so as to acquire a phase distribution originating from the sample.

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.

Projection displays include a highlight projector and a main projector. Highlights projected by the highlight projector boost luminance in highlight areas of a base image projected by the main projector. Various highlight projectors are based on steerable beams, holographic projectors, and spatial light modulators. A Fourier transform component and a mask positioned on the Fourier plane thereof are used to attenuate or eliminate selected spatial frequencies, e.g., to increase peak luminance without raising the black level of the projected image.

An optical device includes a display configured to generate an image light; and a waveguide optically coupled with the display and configured to guide the image light to an exit pupil of the optical device. The waveguide includes an in-coupling element configured to couple the image light into the waveguide, and an out-coupling element configured to decouple the image light out of the waveguide. The out-coupling element includes a grating having a diffraction efficiency gradient along a predetermined direction at a plane of the grating.

A method of manufacturing a full-color holographic optical element in a full-color holographic optical element manufacturing apparatus including a lens and a holographic recording medium located farther away than a focal length of the lens, the method including: allowing a signal beam including a mixture of laser beams having wavelengths of R (Red), G (Green), and B (Blue) to be incident on the lens; and recording a hologram in such a manner that a reference beam including a mixture of laser beams having wavelengths of R, G, and B is allowed to be incident on the holographic recording medium, wherein the holographic recording medium is configured with a single medium.

A laser processing apparatus includes a spatial light modulator for inputting laser light output from a laser light source and outputting laser light after phase modulation by a hologram, and a control unit for presenting, on the spatial light modulator, the hologram for focusing the laser light after the phase modulation output from the spatial light modulator on a plurality of irradiation points in a processing object by a focusing optical system. The control unit controls light intensities of at least two irradiation points included in the plurality of irradiation points independently of each other.