A replicator assembly includes reflective, transmissive, and transparent elements. The reflective element receives and reflects a hologram of a HUD system. The transmissive element includes a partially transmissive portion that receives a reflection of the hologram from the reflective element, outputs N replications of the hologram, and reflects N−1 replications of the hologram. The partially transmissive portion is implemented as a continuous transmission neutral density filter across different phase regions. The phase regions of the partially transmissive portion correspond respectively to the N replications. N is an integer greater than or equal to 2. The reflective element reflects the N−1 replications of the hologram. The transparent element is disposed between the reflective and transmissive elements and guides the N replications of the hologram between the reflective and transmissive elements. The reflective, transmissive and transparent elements are implemented as a replicator and collectively provide the N replications of the hologram.

A holographic display with a spatial light modulator coupled to a pupil-replicating lightguide is disclosed. The spatial light modulator provides a light beam with spatially modulated amplitude and/or phase. The light beam is replicated by the pupil-replicating lightguide into a plurality of portions. The portions interfere at an exit pupil to provide an image for direct observation by a user. An eye-tracking system may be provided to determine the position of the user pupils, and the spatial modulation of the light beam may be adjusted accordingly to make sure that the optical interference of the beam portions at the eye pupils provides the required image.

The technology provides a spectroscopy system having two or more spectrometers with substantially uniform focal lengths. The spectrometers include a detector that converts optical signals into electrical signals to render spectral data. The spectroscopy system includes a computing device that is electrically coupled to one or more detectors to receive the spectral data and compare the spectral data against other spectral data. The other spectral data originates from spectrometers that have substantially similar focal lengths, slit widths, excitation laser wavelengths, or any combination of these. The technology includes an application server that is communicatively coupled to a second spectroscopy system. The application server includes software that enables data sharing among the two or more spectroscopy systems, including sharing the spectral data and the other spectral data. The application server compares sampled spectral data against stored spectral data to identify a match.

In one embodiment, a system may generate a hologram by processing a first image using a machine-learning model. The system may generate a second image based on at least a portion of the hologram using a processing model that is configured to simulate interactions between a light source and the hologram. The system may compare the second image to the first image to calculate a loss based on a loss function. The system may update the machine-learning model based on the loss between the first image and the second image. The updated machine-learning model is configured to process one or more input images to generate one or more corresponding holograms.

A method of producing information from at least one camera image of an object, including: A) recording raw image data of the at least one camera image, B) evaluating the raw image data by a mathematical linkage to produce combination image data, C) deriving the information from the combination image data, D) outputting the information, E) determining an actual measure for a data quality of the raw image data prior to or after evaluation steps in step B), F) determining a deviation between the actual measure for the data quality and a target measure for the data quality of the raw image data of at least one camera image, and G) again recording all raw image data of those camera images, for which the deviation determined in step F) is greater than a predetermined threshold value and repeating at least one evaluation step from step B) and steps C) to F) either until the deviation determined in step F) for the raw image data of all camera images from the plurality of camera images is less than the threshold value or until a predetermined termination condition is fulfilled.

A dielectric based metasurface hologram device includes: a substrate layer provided at a lowermost portion of the dielectric based metasurface hologram device; and a dielectric layer forming a geometric metasurface on the substrate layer. The substrate layer includes a plurality of unit cells which are continuous, and the dielectric layer includes a plurality of nano-structures which are disposed with a predetermined distance therebetween. The single nano-structure is disposed on the unit cell, and a hologram image is formed when an incident light from a light source is reflected by the nano-structure so that a phase of the light is controlled.

A rotational geometric phase hologram has geometric phase optical elements (GPOEs) serially cascaded along a common optical axis to form a GPOE cascade used for receiving a linearly-polarized light beam and generating output light beams at an exit surface of the last GPOE. Interference occurred in the output light beams creates a polarization interference pattern on the exit surface. A photoalignment substrate, when positioned in close proximity to the exit surface, records the pattern. Advantageously, each GPOE is rotatable about the common optical axis. Respective rotation angles of the GPOEs are determined according to a spatially-varying linear polarization orientation distribution selected to be generated for the polarization interference pattern. Particularly, the respective rotation angles are reconfigurable to provide the periodicity required for the spatially-varying linear polarization orientation distribution over a range of allowed periodicities while keeping the periodicity of spatially-varying optic axis orientation distribution of each GPOE to be fixed.

Techniques disclosed herein relate to modifying refractive index modulation in a holographic optical element, such as a holographic grating. According to certain embodiments, a holographic optical element or apodized grating includes a polymer layer comprising a first region characterized by a first refractive index and a second region characterized by a second refractive index. The holographic optical element or apodized grating includes a plurality of nanoparticles dispersed in the polymer layer. The nanoparticles have a higher concentration in either the first region or the second region. In some embodiments, the nanoparticles may be configured to increase the refractive index modulation. In some embodiments, the nanoparticles may be configured to apodize the grating by decreasing the refractive index modulation proximate to sides of the grating. The refractive index may be modulated by applying a monomer reservoir buffer layer to the polymer layer, either before or after hologram fabrication.

A replicator assembly includes reflective, transmissive, and transparent elements. The reflective element receives and reflects a hologram of a HUD system. The transmissive element includes a partially transmissive portion that receives a reflection of the hologram from the reflective element, outputs N replications of the hologram, and reflects N1 replications of the hologram. The partially transmissive portion is implemented as a continuous transmission neutral density filter across different phase regions. The phase regions of the partially transmissive portion correspond respectively to the N replications. N is an integer greater than or equal to 2. The reflective element reflects the N1 replications of the hologram. The transparent element is disposed between the reflective and transmissive elements and guides the N replications of the hologram between the reflective and transmissive elements. The reflective, transmissive and transparent elements are implemented as a replicator and collectively provide the N replications of the hologram.

The technology provides a spectroscopy system having two or more spectrometers with substantially uniform focal lengths. The spectrometers include a detector that converts optical signals into electrical signals to render spectral data. The spectroscopy system includes a computing device that is electrically coupled to one or more detectors to receive the spectral data and compare the spectral data against other spectral data. The other spectral data originates from spectrometers that have substantially similar focal lengths, slit widths, excitation laser wavelengths, or any combination of these. The technology includes an application server that is communicatively coupled to a second spectroscopy system. The application server includes software that enables data sharing among the two or more spectroscopy systems, including sharing the spectral data and the other spectral data. The application server compares sampled spectral data against stored spectral data to identify a match.