A grating coupler may be fabricated by exposing a photopolymer layer to grating forming light for forming periodic refractive index variations in the photopolymer layer. The photopolymer layer may be exposed to apodization light for reducing an amplitude of the periodic refractive index variations in a spatially-selective manner. The apodization may also be achieved or facilitated by subjecting outer surface(s) of the photopolymer layer to a chemically reactive agent that causes the refractive index contrast to be reduced near the surface(s) of application. The apodized refractive index profile of the gratings facilitates the reduction of optical crosstalk between different gratings of the grating coupler.

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 holographic image generation system including a spatial light modulator; a light source; a temporal modulator; a light sensor and a demodulator. The spatial light modulator has pixels. The light source illuminates the spatial light modulator. The temporal light modulator modulates an output intensity of the light source over time to encode holographic data representing a hologram. The light sensor is associated with a spatial light modulator and receives light from the light source and generates a signal representative of the output intensity of the light source. The demodulator is connected to the light sensor to receive the signal. The demodulator decodes the signal to obtain the holographic data. The demodulator is connected to the spatial light modulator to set the pixels of the spatial light modulator in accordance with the holographic data to display the hologram ready for illumination by the light source to form a holographic reconstruction.

A method for three-dimensional imaging of a sample (302) comprises: receiving (102) interference patterns (208) acquired using light-detecting elements (212), wherein each interference pattern (208) is formed by scattered light from the sample (302) and non-scattered light from a light source (206; 306), wherein the interference patterns (208) are acquired using different angles between the sample (302) and the light source (206; 306); performing digital holographic reconstruction applying an iterative algorithm to change a three-dimensional scattering potential of the sample (302) to improve a difference between the received interference patterns (208) and predicted interference patterns based on the three-dimensional scattering potential; wherein the iterative algorithm reduces a sum of a data fidelity term and a non-differentiable regularization term and wherein the iterative algorithm includes a forward-backward splitting method alternating between forward gradient descent (108) on the data fidelity term and backward gradient descent (110) on the regularization term.

A projection system arranged to receive an image for projection. The image is a colour image comprising a first colour component and a second colour component. The system is arranged to calculate a first hologram of the first colour component and a second hologram of the second colour component. The system is further arranged to add content of the second colour component to the first colour component before calculating the first hologram. The first hologram contains information of the first colour component and information of at least a portion of the second colour component. The system is further arranged to form a first holographic reconstruction by illuminating the first hologram with first colour light and to form a second holographic reconstruction by illuminating the second hologram with second colour light. The first holographic reconstruction changes the chromaticity of the at least a portion of the second colour component.

A method and apparatus for generating coherent light, and a display apparatus using coherent light are provided. A wide-angle coherent light generation apparatus may focus parallel light onto a focal point, and may generate coherent light at a wide angle, using an optical device.

Apparatus for detecting a 3D structure of an object, comprising at least three laser emitters and a beam splitter that splits the laser radiation of the laser emitters into a reference radiation and an illumination radiation. The illumination radiation strikes the object to be measured, is reflected by the object as object radiation and interferes with the reference radiation. A detector receives the interference patterns formed from the interference of the reference and object radiation and an analysis unit analyzes the interference patterns. At least two of the laser emitters emit laser radiation in the invisible range and the analysis unit detects the object in three dimensions based on the interference patterns of the invisible laser radiation. At least one of the laser emitters emits colored laser radiation and the analysis unit deduces the object's color based on the intensity of the colored object radiation reflected by the object.

Devices utilizing holographic 4D plenoptic capture and display technologies to generate a light field function to provide glasses-less vision correction for observers with imperfect vision, and to project an image according to the generated light field function, and methods for calibrating a four-dimensional light field for a user with an uncorrected visual acuity.

An illumination device has a coherent light source that emits coherent light beam, and an optical device that diffuses the coherent light beam, wherein the optical device comprises a first diffusion region that diffuses the coherent light beam to illuminate a first area, and a second diffusion region that diffuses the coherent light beam to display predetermined information in a second area.

A video communication system uses a light field display to present a holographic image of a remote scene (e.g., a hologram of a remote participant). The system may include a local light field display assembly and a controller. The controller generates display instructions based on visual data corresponding to a remote scene received from a remote image capture system (e.g., a remote light field display system). The display instructions cause the local light field display assembly to generate a holographic image of the remote scene.