A light irradiation device includes a Gaussian beam output unit for outputting light having a light intensity distribution that conforms to a Gaussian distribution, a spatial light modulator for receiving the light and modulating the light by presenting a CGH, an optical system for converging the modulated light, and an amplitude mask arranged on at least one of an optical axis between the Gaussian beam output unit and the spatial light modulator and an optical axis between the spatial light modulator and the optical system. The amplitude mask has a circular-shaped first region centered on the optical axis and an annular-shaped second region that surrounds the first region. Transmittance in the second region continuously decreases as a distance from the optical axis increases.

A method for generating a holographic image, a signal processor, a holographic image display device, a wearable apparatus, and an onboard head-up display apparatus. The method comprises: performing holographic transformation on the basis of a target amplitude phase distribution of a target image to obtain a holographic phase image; performing phase quantization of the holographic phase image to obtain a quantized holographic image; performing inverse holographic transformation of the quantized holographic image to obtain a reconstructed image; if the reconstructed image satisfies a preset condition, determining that the quantized holographic image is a target holographic image; if not, constraining the amplitude phase of the reconstructed image and, on the basis of the amplitude phase constrained image, continuing iteration. The present method can rapidly and effectively implement monochrome or multi-colour high contrast ratio, low noise real-time holographic image generation and display, and the imaging distance can be freely adjusted.

A system includes a plurality of optical identifiers and a reader for the optical identifiers. Each optical identifier has an optical substrate and a volume hologram (e.g., with unique data, such as a code page) in the optical substrate. The reader for the optical identifiers includes an illumination source (e.g., a laser), and a camera. The illumination source is configured to direct light into a selected one of the optical identifiers that has been placed into the reader to produce an image of the associated volume holograms at the camera. The camera is configured to capture the image. The captured image may be stored in a digital format by the system.

A light detection and ranging, LiDAR, system arranged to make time of flight measurements of a scene. The LiDAR system comprises a holographic projector comprising: a spatial light modulator arranged to display light modulation patterns, each light modulation pattern comprising a hologram and a grating function having a periodicity; a light source arranged to illuminate each displayed light modulation pattern in turn; and a projection lens arranged to receive spatially modulated light from the spatial light modulator and project a structured light pattern corresponding to each hologram onto a respective replay plane. The LiDAR system further comprises a system controller arranged to receive distance information related to the scene and output to the holographic projector a control signal corresponding to the distance information. The holographic projector is arranged to use the control signal to determine a parameter for projection of a subsequent structured light pattern.

A system includes a multiplexed optical identifier and a reader for the optical identifier. The multiplexed optical identifier includes an optical substrate, and a plurality of volume holograms in the optical substrate. The reader includes an illumination source and a camera. The illumination source is configured to direct light into the optical identifier to produce an image of a corresponding one of the volume holograms at the camera, and the camera is configured to capture the image, which is stored in a digital format by the system. The multiplexed optical identifier contains more than one code page, wherein each of the code pages is used for a different purpose.

A method for irradiating a medium includes irradiating the medium with an electromagnetic wave which is scattered in the medium and modulated in frequency at a position in the medium; obtaining information corresponding to an interference pattern generated by interference between the modulated electromagnetic wave and a reference wave; and generating a phase conjugate wave, based on the obtained information, which irradiates the medium.

An infrared image is captured by an image sensor and a frequency domain infrared image is generated by performing a Fourier transform operation on the infrared image. A filtered frequency domain infrared image is generated by applying a mask to the frequency domain infrared image. A spatial domain infrared image is generated by performing an inverse Fourier transform on the filtered frequency domain infrared image. Phase data is extracted from the spatial domain infrared image and a holographic pattern generated from the phase data is driven onto a display.

An optically trapped atom transfer tweezer includes an optical modulator which modulates incident light and generates a first hologram; a first lens which images the first hologram on an intermediate image plane and generates a first holographic image having any potential shape; a second lens which re-images the first holographic image on an entrance pupil of a third lens; the third lens which re-images a second hologram generated by the re-imaging of the second lens on a plane where an optically trapped atom array exists; a photographing device which captures optically trapped cold atoms from a second holographic image generated on the plane where an optically trapped atom array exists; and a controller which controls the optical modulator to adjust the second holographic image on the basis of the optically trapped atom image captured by the photographing device such that the optically trapped atom array is transferred to any spatial position.

A system includes a plurality of optical identifiers and a reader for the optical identifiers. Each optical identifier has an optical substrate and a volume hologram (e.g., with unique data, such as a code page) in the optical substrate. The reader for the optical identifiers includes an illumination source (e.g., a laser), and a camera. The illumination source is configured to direct light into a selected one of the optical identifiers that has been placed into the reader to produce an image of the associated volume holograms at the camera. The camera is configured to capture the image. The captured image may be stored in a digital format by the system.

A system includes a plurality of optical identifiers and a reader for the optical identifiers. Each optical identifier has an optical substrate and a volume hologram (e.g., with unique data, such as a code page) in the optical substrate. The reader for the optical identifiers includes a laser, and a camera. The laser is configured to direct laser light into a selected one of the optical identifiers that has been placed into the reader to produce an image of the associated volume holograms at the camera. The camera is configured to capture the image. The captured image may be stored in a digital format by the system.