Methods, apparatus, devices, and systems for three-dimensional (3D) displaying objects are provided. In one aspect, a method includes obtaining data including respective primitive data for primitives corresponding to an object, determining an electromagnetic (EM) field contribution to each element of a display for each of the primitives by calculating an EM field propagation from the primitive to the element, generating a sum of the EM field contributions from the primitives for each of the elements, transmitting to each of the elements a respective control signal for modulating at least one property of the element based on the sum of the EM field contributions, and transmitting a timing control signal to an illuminator to activate the illuminator to illuminate light on the display, such that the light is caused by the modulated elements of the display to form a volumetric light field corresponding to the object.

A holographic system comprises an image processor, a hologram calculator and a display driver. The image processor is arranged to determine first and second secondary images by sampling the pixel values of a primary image at a regular array of sampling positions. The hologram calculator is arranged to determine a hologram of each secondary image. The display driver is arranged to display each hologram in rapid succession on a display device, first and second times, so as to reconstruct each secondary image from the respective hologram such that respective first and second arrays of image pixels corresponding to the primary image are perceivable. Image pixels of the reconstruction of the second secondary image are interposed between image pixels of the reconstruction of the first secondary image in the first direction.

Systems and methods for generating a controlled sound field. In one example, the system and method perform or include receiving a sound wave emitted from a sound source; determining, with an electronic processor, a pattern of at least one of an amplitude change and a phase change necessary to create a desired sound field using the sound wave; determining, with the electronic processor, a plurality of passive sound-modulating elements needed to generate the pattern of at least one of the amplitude change and the phase change; and constructing the plurality of sound-modulating elements to generate the controlled sound field.

Virtual reality (VR) displays are computer displays that present images or video in a manner that simulates a real experience for the viewer. In many cases, VR displays are implemented as head-mounted displays (HMDs) which provide a display in the line of sight of the user. Because current HMDs are composed of a display panel and magnifying lens with a gap therebetween, proper functioning of the HMDs limits their design to a box-like form factor, thereby negatively impacting both comfort and aesthetics. The present disclosure provides a different configuration for a VR display which allows for improved comfort and aesthetics, including specifically at least one coherent light source, at least one pupil replicating waveguide coupled to the at least one coherent light source to receive light therefrom, and at least one spatial light modulator coupled to the at least one pupil replicating waveguide to modulate the light.

A method comprises obtaining input data comprising a hologram of a 3-dimensional (3D) particle field, a depth map of the 3D particle field, and a maximum phase projection of the 3D particle field. The method also comprises applying a U-net convolutional neural network (CNN) to the input data to generate output data. Encoder blocks have residual connections between a first layer and a second layer that skips over a convolution layer of the encoder block. Decoder blocks have residual connections between a first layer and a second layer that skips over a convolution layer of the decoder block. The output data includes a channel in which pixel intensity corresponds to relative depth of particles in the 3D particle field and an output image indicating locations of centroids of the particles in the 3D particle field.

A holographic security or identification device (10) comprises an object, or a flexible substrate (12) configured to be conformable to a desired, curved shape; and a plurality of structures (14) formed on or in the object to have a desired curved configuration, or formed in or associated with the substrate and arranged to adopt a desired curved configuration when the substrate is conformed to a desired shape, wherein the plurality of structures (14) are configured to receive light (20) of a selected at least one wavelength or range of wavelengths and to produce, using the received light, a desired holographic image (22) for security or identification purposes when in the desired configuration.

Techniques related to generating holographic images are discussed. Such techniques include application of a machine learning model to the target image to generate data that is used to enable the determination of a phase pattern via an iterative propagation feedback model. The iterative propagation feedback model is used to generate a feedback strength value, which is then used to generate a phase diffraction pattern for presentation at a holographic plane.

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, an optical device includes: a first optically diffractive component including a first diffractive structure configured to diffract a first color of light having a first incident angle at a first diffracted angle, a second optically diffractive component including a second diffractive structure configured to diffract a second color of light having a second incident angle at a second diffracted angle, a first reflective layer configured to totally reflect the first color of light having the first incident angle and transmit the second color of light, and a second reflective layer configured to totally reflect the second color of light having the second incident angle. The first reflective layer is between the first and second diffractive structures, and the second diffractive structure is between the first and second reflective layers.

An apparatus includes a phase light modulator (PLM) configured to produce background image illumination including background image light and zero-order light, a first lens array including first lenses optically coupled to the PLM and configured to project the background image light, a second lens array optically coupled to the first lens array and including second lenses configured to project the background image light, an optical tunnel extending between the first lens array and the second lens array, optically coupled to the PLM and configured to project a zero-order light, an embedded lens in the second lens array optically coupled to the optical tunnel and configured to focus the zero-order light from the optical tunnel, and focusing optics optically coupled to the second lens array and the embedded lens and configured to focus the background image light and the zero-order light onto a background image plane of a spatial light modulator.

A holographic imaging device and method realizes both a transmission type and a reflection type, and also realizes a long working distance wide field of view or ultra-high resolution. Object light emitted from an object, sequentially illuminated with parallel illumination light whose incident direction is changed, is recorded on a plurality of object light holograms for each incident direction using off-axis spherical wave reference light. The reference light is recorded on a reference light hologram using in-line spherical wave reference light being in-line with the object light. An object light wave hologram and its spatial frequency spectrum at the object position are generated for each incident direction using each hologram. A synthetic spectrum which occupies a wider frequency space is generated by matching each spectrum in the overlapping area, and a synthetic object light wave hologram with increased numerical aperture is obtained thereby.