A holographic display apparatus and a hologram optimization method for the apparatus are provided. The holographic display apparatus includes a focus-forming optical element configured to form a plurality of foci by receiving plane waves; a collimating lens configured to propagate, as plane waves, light incident through the plurality of foci; and a spatial light modulator configured to generate a holographic image by overlapping a plurality of plane waves incident from the collimating lens.

Differential Holography technology measures the amplitude and/or phase of, e.g., an incident linearly polarized spatially coherent quasi-monochromatic optical field by optically computing the first derivative of the field and linearly mapping it to an irradiance signal detectable by an image sensor. This information recorded on the image sensor is then recovered by a simple algorithm. In some embodiments, an input field is split into two or more beams to independently compute the horizontal and vertical derivatives (using amplitude gradient filters in orthogonal orientations) for detection on one image sensor in separate regions of interest (ROIs) or on multiple image sensors. A third unfiltered beam recorded in a third ROI directly measures amplitude variations in the input field to numerically remove its contribution as noise before recovering the original wavefront using a numerical in algorithm. When combined, the measured amplitude and phase constitute a holographic recording of the incident optical field.

Disclosed herein are an apparatus and method for calculating homography of a Fourier propagation structure. The method for calculating homography of a Fourier propagation structure includes generating a point array image, inserting a certain frame into an edge of the point array image, generating a phase hologram based on the point array image, perform optical restoration and camera capturing on the phase hologram, extracting a point array from each of an optically restored image and a camera-captured image, and calculating homography based on the extracted point array.

A lens-less system for holographic imaging or a holographic imaging device is provided. The method/device includes a stationary image sensor to capture an image of a sample illuminated by light from a stationary illumination source. A reference lens-less holographic image may be captured and used as a base line to reduce image artifacts and/or remove noise from the lens-less holographic image. Since real wavefronts produced by a diverging point source are neither perfectly spherical nor planar but a combination of both qualities, theoretical estimates for wavefront reconstruction based on perfectly planar or spherical incident waves cannot be applied accurately. The method/device here provides a solution by performing a calibrated wavefront reconstruction based on equations governing coherent light propagation for both spherical waves and planar waves with a mathematical correlation between numerical magnification and propagation depth to produce accurate three-dimensional details of the object.

A lens-less system for holographic imaging or a holographic imaging device is provided. The method/device includes a stationary image sensor to capture an image of a sample illuminated by light from a stationary illumination source. A reference lens-less holographic image may be captured and used as a base line to reduce image artifacts and/or remove noise from the lens-less holographic image. Since real wavefronts produced by a diverging point source are neither perfectly spherical nor planar but a combination of both qualities, theoretical estimates for wavefront reconstruction based on perfectly planar or spherical incident waves cannot be applied accurately. The method/device here provides a solution by performing a calibrated wavefront reconstruction based on equations governing coherent light propagation for both spherical waves and planar waves with a mathematical correlation between numerical magnification and propagation depth to produce accurate three-dimensional details of the object.

An optical measurement system includes a first light source that generates near infrared rays, a silicon-based image sensor, and an optical system including a beam splitter that divides light from the first light source into first light and second light. The optical system records with the image sensor, a first hologram resulting from modulation with second light, of light obtained by illumination of a sample with the first light, the second light being diverging light.

The present invention provides a holographic imaging device and a holographic imaging method that have improved performance in which the influence of a refractive index of a cube-type beam coupler constituting an optical system is considered. The holographic imaging device 1 comprises the beam coupler 3 consisting of the cube-type beam splitter arranged between the object 4 and the image sensor 5 and the calculation reference light hologram generation unit 14 for generating an inline reference light hologram j.sub.L representing a light wave on the hologram plane 50 by performing a light wave propagation calculation including propagation inside the beam coupler 3, on a spherical wave emitted from the condensing point P2 of the inline spherical wave reference light L. The inline reference light hologram j.sub.L is a computer-generated hologram and used for generating an object light hologram g by removing component of the reference light L from a complex-amplitude inline hologram J.sub.OL representing the object light O and the inline spherical wave reference light L on the hologram plane 50.

A lens-less system for holographic imaging or a holographic imaging device is provided. The method/device includes a stationary image sensor to capture an image of a sample illuminated by light from a stationary illumination source. A reference lens-less holographic image may be captured and used as a base line to reduce image artifacts and/or remove noise from the lens-less holographic image. Since real wavefronts produced by a diverging point source are neither perfectly spherical nor planar but a combination of both qualities, theoretical estimates for wavefront reconstruction based on perfectly planar or spherical incident waves cannot be applied accurately. The method/device here provides a solution by performing a calibrated wavefront reconstruction based on equations governing coherent light propagation for both spherical waves and planar waves with a mathematical correlation between numerical magnification and propagation depth to produce accurate three-dimensional details of the object.