The present invention relates to the technical fields of optical imaging, microwave imaging, radar detection, sonar, ultrasonic imaging, and target detection, imaging identification and wireless communication based on media such as sound, light and electricity, and in particular, to a fast imaging method suitable for passive imaging and active imaging and application of the fast imaging method in the above fields. According to the method provided by the present invention, image field distribution corresponding to a target is achieved based on a lens imaging principle, in combination with an electromagnetic field theory, according to a target signal received by an antenna array, through the amplitude and phase weighting of a unit signal and by using an efficient parallel algorithm. The method provided by the present invention has the advantages of capability of being compatible with passive imaging and holographic imaging, good imaging effect, small operation amount, low hardware cost, high imaging speed and suitability for long-distance imaging, and can be widely applied in the fields of optical imaging, microwave imaging, radar detection, sonar, ultrasonic imaging, and target detection, imaging identification and wireless communication based on media such as sound, light and electricity.

A holographic imaging device is disclosed. In one aspect, the holographic imaging device comprises an imaging unit comprising at least two light sources, wherein the imaging unit is configured to illuminate an object by emitting at least two light beams with the at least two light sources. A first and second light beams have different wave-vectors and wavelengths. The holographic imaging device further comprises a processing unit configured to obtain at least two holograms of the object by controlling the imaging unit to sequentially illuminate the object with respectively the first light beam and the second light beam, construct at least two 2D image slices based on the at least two holograms, wherein each 2D image slice is constructed at a determined depth within the object volume, and generate a three-dimensional image of the object based on a combination of the 2D image slices.

The present invention provides a surface shape measuring device and a surface shape measuring method which do not require a physical reference plane and can improve measurement accuracy without using a mechanical adjustment mechanism. The illumination light condensing point P.sub.Q and the reference light condensing point P.sub.L are arranged as mirror images of each other with respect to the virtual plane VP, and each data of the object light O, being a reflected light of the spherical wave illumination light Q, and the inline spherical wave reference light L is recorded on each hologram. On the virtual plane VP, the reconstructed object light hologram h.sup.V for measurement is generated, and the spherical wave optical hologram s.sup.V representing a spherical wave light emitted from the reference light condensing point P.sub.L is analytically generated. The height distribution of the surface to be measured of the object 4 is obtained from the phase distribution obtained by dividing the reconstructed object light hologram h.sup.V by the spherical wave light hologram s.sup.V. High-accuracy surface shape measurement without requiring a reference plane such as a glass substrate is realized by comparing the phase data of the reflected light acquired from the surface to be measured and the phase distribution on the plane cut surface of the spherical wave obtained analytically.

An interference imaging device includes a light interference generator that includes: a light wave splitter configured to reflect a part of incident light and to allow a remaining part of the incident light to pass through; a phase modulator configured to modulate a phase of incident light that has passed through the light wave splitter; and a reflector configured to reflect the phase-modulated incident light from the phase modulator so that the reflected, phase-modulated incident light overlaps with incident light that has been reflected by the light wave splitter.

An information processing apparatus that executes processing of obtaining, from an interference fringe image that is a two-dimensional distribution of intensity of interference fringes of object light and reference light, a phase difference image that is a two-dimensional distribution of a phase difference between the object light and the reference light, and obtaining a shape of an object to be observed based on the phase difference image includes at least one processor configured to acquire object-related information regarding the object to be observed, read out, from a storage unit in which the object-related information and a shape profile indicating the shape of the object to be observed are stored in association with each other, the shape profile corresponding to the acquired object-related information, and perform phase connection with respect to the phase difference image with reference to the read-out shape profile.

A cell area extraction unit (241) extracts a cell area in a phase image that is created based on a hologram obtained by in-line holographic microscope (IHM). A background value acquisition unit (242) obtains a background value from phase values at a plurality of positions outside the cell area. An intracellular phase value acquisition unit (243) averages a plurality of phase values on a sampling line set at a position close to the periphery of a cell, while avoiding a central portion in which the phase value may be lowered in the cell area, to obtain an intracellular phase value. A phase change amount calculation unit (244) obtains the difference between the intracellular phase value and the background value. A phase change amount determination unit (245) compares the value of the difference with thresholds in two levels to determine whether the cell is in an undifferentiated state or an undifferentiation deviant state. It is thereby possible to automatically make a correct determination while removing the influence of a theoretical measurement error by IHM.

A device for detecting particles in air; said device comprising: a flow channel configured to allow a flow of air comprising particles through the flow channel; a light source configured to illuminate the particles, such that an interference pattern is formed by interference between light being scattered by the particles and non-scattered light from the light source; an image sensor configured to detect incident light, detect the interference pattern, and to acquire a time-sequence of image frames, each image frame comprising a plurality of pixels, each pixel representing a detected intensity of light; and a frame processor configured to filter information in the time-sequence of image frames, wherein said filtering comprises:
identifying pixels of interest in the time-sequence of image frames, said pixels of interest picturing an interference pattern potentially representing a particle in the flow of air, and outputting said identified pixels of interest for performing digital holographic reconstruction.

The invention relates to a free-beam interferometric method for illuminating a sequence of sectional areas in the interior of the light-scattering object. The method makes it possible for the user to select a larger image field and/or a higher image resolution than previously possible with the occurrence of self-interference of the specimen light from a scattering specimen.

A method for multi-spectral scattering-matrix tomography includes a step of splitting an input light signal into an incident light signal and a reference light signal. The sample light signal is directed to a sample in either a reflection configuration or a transmission configuration such that an output light signal includes light scattered from or transmitted through the sample. The incident signal and the reference light signal are directed to a camera angled to allow for amplitude and phase to be calculated by off-axis holography. A total light signal is measured with a camera that is a coherent sum of the reference light signal and the output signal. The total light signal for each light frequency and each incident angle are collected as collected total light signal data. A computing device derives an image of the sample from a calculated reflection matrix or transmission matrix or both of them.

The illumination light condensing point P.sub.Q and the reference light condensing point P.sub.L are arranged as mirror images of each other with respect to the virtual plane VP, and each data of the object light O, being a reflected light of the spherical wave illumination light Q, and the inline spherical wave reference light L is recorded on each hologram. On the virtual plane VP, the reconstructed object light hologram h.sup.V for measurement is generated, and the spherical wave optical hologram s.sup.V representing a spherical wave light emitted from the reference light condensing point P.sub.L is analytically generated. The height distribution of the surface to be measured of the object 4 is obtained from the phase distribution obtained by dividing the reconstructed object light hologram h.sup.V by the spherical wave light hologram s.sup.V.