A laser beam (L50) generated by a laser light source (50) is reflected by a light beam scanning device (60), and irradiated onto a hologram recording medium (45). On the hologram recording medium (45), an image (35) of a scatter plate is recorded as a hologram by using reference light that converges on a scanning origin (B). The light beam scanning device (60) bends the laser beam (L50) at the scanning origin (B) and irradiates it onto the hologram recording medium (45). At this time, scanning is carried out by changing the bending mode of the laser beam with time so that the irradiation position of the bent laser beam (L60) on the hologram recording medium (45) changes with time. Regardless of the beam irradiation position, diffracted light (L45) from the hologram recording medium (45) reproduces the same reproduction image (35) of the scatter plate at the same position. An illumination spot in which speckles are reduced is formed on the light receiving surface (R) of an illuminating object (70) by the reproduction image (35) of the hologram.

An apparatus for capturing a Fourier hologram splits a coherent light source into an object beam and a reference beam, sets a distance of a virtual focal plane of a subject, generates spherical wave field data propagated from a point source of the virtual focal plane to a central coordinate plane of a spatial light modulator, generates a spherical wave field on a space from the spherical wave field data and the reference beam by the spatial light modulator, synthesizes an object wave field generated by reflecting the object beam by the subject and the spherical wave field with each other so that an interference pattern is formed on the image sensor face, captures the interference pattern formed on the image sensor face, and then performs Fourier transformation to calculate an object wave field formed on the focal plane of the subject.

A method of obtaining a focus term by using a periodicity of the focus term is provided. The focus term may be used in a plurality of operation processes for processing image data.

A device in holographic imaging comprises: at least two light sources, wherein each of the at least two light sources is arranged to output light of a unique wavelength; and at least one holographic optical element, wherein the at least two light sources and the at least one holographic optical element are arranged in relation to each other such that light from the at least two light sources incident on the at least one holographic optical element interacts with the at least one holographic optical element to form wavefronts of similar shape for light from the different light sources.

A differentiation system for differentiating cells includes an input device configured to receive holographic image data of a microscopic particle in suspension, holographic image data processing logic for converting the holographic image data to the frequency domain by performing a Fourier transform of the holographic image data, and a recognizer configured to determine characterization features of the holographic image data of the microscopic particle in the frequency domain for characterization of the microscopic particle, the characterization features comprising rotationally invariant features.

A method for observation of a sample, the sample comprising microorganisms immersed in a nontransparent culture medium, the culture medium being favorable to the development of the microorganisms, the sample being arranged between a light source and an image sensor, the method comprising: a) illuminating the sample with the light source, the light source emitting light propagating along an axis of propagation; b) acquiring an image of the sample by the image sensor; c) from the image acquired, characterization of the microorganisms; the method being characterized in that: the culture medium extends, parallel to the axis of propagation, to a thickness of less than 500 m.

An illumination apparatus using a coherent light source, including a light beam scanning device that irradiates a light beam onto a hologram recording medium, and scans the light beam so that an irradiation position of the light beam on the hologram recording medium changes with time. The light beam scanning device scans the light beam so that an irradiation direction of the light beam with respect to the hologram recording medium is along the particular optical path, the light beam scanning device having a function of bending the light beam at a fixed scanning origin so that the light beam swings around the fixed scanning origin on a plane including the fixed scanning origin, and scans the light beam in a one-dimensional direction on the hologram recording medium. Illumination light obtained from the hologram recording medium is irradiated onto a light receiving surface.

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.

Among other things, a method comprises imaging a sample displaced between a sensor surface and a surface of a microscopy sample chamber to produce an image of at least a part of the sample. The image is produced using lensless optical microscopy, and the sample contains at least blood from a subject. The method also comprises automatically differentiating cells of different types in the image, generating a count of one or more cell types based on the automatic differentiation, and deriving a radiation dose the subject has absorbed based on the count.

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.