A method for observing a sample (10), the sample lying in a plane of the sample defining radial coordinates, the method comprising the following steps: a) illuminating the sample using a light source (11), able to emit an incident light wave (12) that propagates toward the sample along a propagation axis (Z); b) acquiring, using an image sensor (16), an image (I.sub.0) of the sample (10), said image being formed in a detection plane (P.sub.0), the sample being placed between the light source (11) and the image sensor (16), such that the incident light wave sees an optical path difference, parallel to the propagation axis (Z), by passing through the sample; c) processing the image acquired by the image sensor;
wherein the processing of the acquired image comprises taking into account vectors of parameters, respectively defined at a plurality of radial coordinates, in the plane of the sample, each vector of parameters being associated with one radial coordinate, and comprising a term representative of an optical parameter of the sample, at least one optical parameter being an optical path difference induced by the sample at the radial coordinate, the vectors of parameters describing the sample.

Both a hologram and fluorescence are simultaneously captured in a state in which they can be reconstructed separately. A recording device (10) includes: a laser light source (LS1) which irradiates a subject (13) with object illumination light so that object light is generated; and an image capturing device (12) which captures (i) a hologram formed by interference between reference light and object light and (ii) an image of fluorescence, and the object illumination light further excites a fluorescent material (14) contained in the subject (13).

A display system comprising a first plurality of pixels, a second plurality of pixels, a first Fourier transform lens and a second Fourier transform lens. The first plurality of pixels is arranged ranged to display first holographic data corresponding to a first holographic reconstruction and receive light of a first wavelength. The a second plurality of pixels is arranged to display second holographic data corresponding to a second holographic reconstruction and receive light of a second wavelength. The first Fourier transform lens is arranged to receive spatially modulated light having a first wavelength from the first plurality of pixels and perform an optical Fourier transform of the received light to form the first holographic reconstruction at a replay plane, wherein the first holographic reconstruction is formed of light at the first wavelength. The second Fourier transform lens is arranged to receive spatially modulated light having a second wavelength from the second plurality of pixels and perform an optical Fourier transform of the received light to form the second holographic reconstruction at the replay plane, wherein the second holographic reconstruction is formed of light at the second wavelength. The optical path length from the first Fourier transform lens to the replay plane is not equal to the optical path length from the second Fourier transform lens to the replay plane.

A holographic projector having an optical path is described. The holographic projector comprises a first spatial light modulator arranged to display a first hologram, and a first light source. The first light source is arranged to illuminate the first spatial light modulator with light of a first wavelength such that a first holographic reconstruction corresponding to the first hologram is formed on a replay plane. The holographic projector further comprises a continuous block of transparent material. At least part of the optical path is formed through the continuous block of transparent material. The transparent material has a refractive index greater than air.

Embodiments of the present disclosure include apparatuses and method for a stacked light emitting diode (LED) hologram display. A stacked LED hologram display can include a first array of LEDs that are configured to emit red light received by a meta-optics panel configured to display a first portion of a holographic image, a second array of LEDs that are configured to emit green light received by a meta-optics panel configured to display a second portion of a holographic image, and a third array of LEDs that are configured to emit blue light received by a meta-optics panel configured to display a third portion of a holographic image. The stacked LED hologram display can include a number of actuators configured to adjust a position of a first array of LEDs in first direction and a second direction, adjust a position of a second array of LEDs in the first direction and the second direction, and adjust a position of a third array of LEDs in the first direction and the second direction.

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 holographic head-up display (HUD) including: a picture generation unit (PGU) including at least one laser light source to generate an optical image to be projected on a HUD; a first mirror to reflect the optical image from the PGU; a second mirror to reflect the optical image reflected by the first mirror; and a holographic optical element (HOE) to diffract the optical image reflected by the second mirror at a first diffraction angle to provide an output optical image in a target direction. The first mirror includes a reflective compensatory HOE to diffract the optical image from the PGU at a second diffraction angle, and in response to change of a wavelength of the optical image from the PGU, the reflective compensatory HOE is configured to diffract the optical image from the PGU at a third diffraction angle different from the second diffraction angle such that the HOE provides the output optical image in the target direction.

A holographic display system including a first spatial light modulator panel and a second spatial light modulator panel is provided. The first spatial light modulator panel is configured to receive a first light with a first color, and generate a first diffracted light with the first color. The second spatial light modulator panel is configured to receive a second light with a second color and a third light with a third color, and respectively generate a second diffracted light with the second color and a third diffracted light with the third color. The first color, the second color, and the third color are different colors, and the first diffracted light, the second diffracted light and the third diffracted light form holographic images. A method for generating holographic images is also provided.

In described examples, a system (e.g., a projection system) can include a diffractive optical element adapted to be illuminated by at least one coherent light beam. A lens array is coupled to receive a diffracted beam of light from the diffractive optical element. The lens array includes a first and a second array lens. The first array lens is coupled to receive a first sector of a pattern of illumination of the diffracted beam of light, and the second array lens is coupled to receive a second sector of the pattern of illumination of the diffracted beam of light. A spatial light modulator is coupled to receive overlapping diffracted beams of light from the first and second array lenses to form an image beam.

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.