A method includes receiving collimated light from an optical imaging system and dividing the received light into multiple bands of wavelength. Each band is refocused onto a corresponding diffraction grating having an amplitude function matched to a point spread function (PSF) of the optical imaging system. The light that is not filtered out by the diffraction grating is transmitted onto a corresponding pixel array. An image is reconstructed from data provided by the pixel arrays for each band. The intensity of light scattered by each diffraction grating may be detected, with the image being reconstructed as a function of an average value of detected intensity of scattered light used to scale the known zero-order mode profile, which is added to the image on the pixel array.

An optical device includes a refractive prism including a first surface facing an object, a second surface facing a first lens, and a third surface configured to reflect incident light to change a path of the incident light, one of the first surface, the second surface, or both the first and the second surface includes a pattern such that the refractive prism is a diffractive optical element; and a plurality of lenses including the first lens.

An all-optical Diffractive Deep Neural Network (D.sup.2NN) architecture learns to implement various functions or tasks after deep learning-based design of the passive diffractive or reflective substrate layers that work collectively to perform the desired function or task. This architecture was successfully confirmed experimentally by creating 3D-printed D.sup.2NNs that learned to implement handwritten classifications and lens function at the terahertz spectrum. This all-optical deep learning framework can perform, at the speed of light, various complex functions and tasks that computer-based neural networks can implement, and will find applications in all-optical image analysis, feature detection and object classification, also enabling new camera designs and optical components that can learn to perform unique tasks using D.sup.2NNs. In alternative embodiments, the all-optical D.sup.2NN is used as a front-end in conjunction with a trained, digital neural network back-end.

Display devices include waveguides with in-coupling optical elements that mitigate re-bounce of in-coupled light to improve overall in-coupling efficiency and/or uniformity. A waveguide receives light from a light source and/or projection optics and includes an in-coupling optical element that in-couples the received light to propagate by total internal reflection in a propagation direction within the waveguide. Once in-coupled into the waveguide the light may undergo re-bounce, in which the light reflects off a waveguide surface and, after the reflection, strikes the in-coupling optical element. Upon striking the in-coupling optical element, the light may be partially absorbed and/or out-coupled by the optical element, thereby effectively reducing the amount of in-coupled light propagating through the waveguide. The in-coupling optical element can be truncated or have reduced diffraction efficiency along the propagation direction to reduce the occurrence of light loss due to re-bounce of in-coupled light, resulting in less in-coupled light being prematurely out-coupled and/or absorbed during subsequent interactions with the in-coupling optical element.

A method for designing a phase-typed diffraction suppressing optical device (12) for a transparent display screen(11) is disclosed, which comprises: acquiring a light field complex amplitude distribution U(x2,y2,d)=A(x2,y2,d)exp(iφ20(x2,y2,d)) on a plane with a distance d from the transparent display screen (12) after a plane wave is transmitted through the screen; and designing the diffraction suppressing optical device (12), so that it has a transmittance function t2 (x2,y2)=exp(iφ21(x2,y2)) and satisfies φ20 (x2,y2,d)+φ21 (x2,y2)=C, where C is a constant. A diffraction suppressing optical device (12) and an under-screen camera apparatus (1) comprising the same are disclosed. The phase-typed diffraction suppressing optical device (12) suppresses the diffraction effect in the under-screen camera apparatus (1) by providing phase modulation, thereby improving the quality of under-screen imaging.

Provided are methods for geometric intrinsic camera calibration using a diffractive optical element. Some methods described include receiving, by at least one processor, at least one image captured by a camera based on a plurality of light beams received from a diffractive optical element aligned with an optical axis of the camera, the plurality of light beams having a plurality of propagation directions associated with a plurality of view angles. The at least one processor identifies a plurality of shapes in the image, determines a correspondence between the plurality of shapes in the image and the plurality of light beams, and identifies one or more intrinsic parameters of the camera that minimize a reprojection error function based on the plurality of shapes in the image and the plurality of propagation directions. Systems and computer program products are also provided.

Examples are provided related to using multiplexed diffractive elements to improve eye tracking systems. One example provides a head-mounted display device comprising a see-through display system comprising a transparent combiner having an array of diffractive elements, and an eye tracking system comprising one or more light sources configured to direct light toward an eyebox of the see-through display system, and also comprising an eye tracking camera. The array of diffractive elements comprises a plurality of multiplexed diffractive elements configured to direct images of a respective plurality of different perspectives of the eyebox toward the eye tracking camera.

A method of fabricating an imaging system as well as to a corresponding imaging system. The method includes providing a substrate; and forming, by means of a 3D-printing technique, a 3D structure on the substrate, wherein the forming of the 3D structure includes forming a stack of at least two diffractive optical elements in a single printing step.

An optical device includes a first waveguide having a first side and an opposing second side, a spatial light modulator configured to project image light, one or more lenses disposed between the spatial light modulator and the first waveguide, and a first in-coupler coupler coupled with the first waveguide. The spatial light modulator is positioned on the first side of the first waveguide. The first in-coupler is positioned to receive the image light projected by the spatial light modulator and transmitted through the one or more lenses and to redirect at least a first portion of the image light so that the first portion of the image light enters the first waveguide and undergoes total internal reflection inside the first waveguide.

An atmosphere starry sky light for festival entertainment is provided. The constellation unit is configured to switch patterns of twelve constellations and perform projection display on the patterns of the twelve constellations. The starry sky unit is configured to project a starry sky background. The background unit is configured to project patterns of aurora, clouds, and ripples. The planetary unit is configured to switch patterns of a planet, and to project and display a planetary image. The constellation unit, the planetary unit, the starry sky unit and the background unit form a panoramic image of the cosmic starry sky by superimposing and combining.