Abstract:
Systems and methods are described for obtaining two-wavelength differential-phase holograms. A method includes determining a difference between a filtered analyzed recorded first spatially heterodyne hologram phase and a filtered analyzed recorded second spatially-heterodyned hologram phase.
Abstract:
A device (1) for sorting objects immersed in a flowing medium is described. The device comprises a holographic imaging unit comprising a plurality of holographic imaging elements (2), a fluid handling unit comprising a plurality of microfluidic channels (3) for conducting flowing medium along a corresponding holographic imaging element (2) and comprising a microfluidic switch (5) arranged downstream of an imaging region in the microfluidic channel for controllably directing each object in the flowing medium into a selected one of a plurality of outlets (6). The device also comprises a processing unit (7) adapted for real-time characterization of the holographic diffraction image obtained for each of the objects thereby taking into account at least one predetermined object type signature. The processing unit (7) furthermore is adapted for controlling the microfluidic switch (5) in response to the characterization.
Abstract:
The invention concerns a method and an apparatus for measuring and computing the Amplitude Point Spread Function (APSF). The invention may be advantageously used in the field of Digital Holographic Microscopy (DHM).
Abstract:
Systems and methods are described for faster processing of multiple spatially-heterodyned direct to digital holograms. A method includes of obtaining multiple spatially-heterodyned holograms, includes: digitally recording a first spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; digitally recording a second spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded first spatially-heterodyned hologram by shifting a first original origin of the recorded first spatially-heterodyned hologram including spatial heterodyne fringes in Fourier space to sit on top of a spatial-heterodyne carrier frequency defined as a first angle between a first reference beam and a first object beam; applying a first digital filter to cut off signals around the first original origin and performing an inverse Fourier transform on the result; Fourier analyzing the recorded second spatially-heterodyned hologram by shifting a second original origin of the recorded second spatially-heterodyned hologram including spatial heterodyne fringes in Fourier space to sit on top of a spatial-heterodyne carrier frequency defined as a second angle between a second reference beam and a second object beam; and applying a second digital filter to cut off signals around the second original origin and performing an inverse Fourier transform on the result, wherein digitally recording the first spatially-heterodyned hologram is completed before digitally recording the second spatially-heterodyned hologram and a single digital image includes both the first spatially-heterodyned hologram and the second spatially-heterodyned hologram.
Abstract:
Systems and methods are described for recording multiple spatially-heterodyned direct to digital holograms in one digital image. A method includes digitally recording, at a first reference beam-object beam angle, a first spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded first spatially-heterodyned hologram by shifting a first original origin of the recorded first spatially-heterodyned hologram to sit on top of a first spatial-heterodyne carrier frequency defined by the first reference beam-object beam angle; digitally recording, at a second reference beam-object beam angle, a second spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded second spatially-heterodyned hologram by shifting a second original origin of the recorded second spatially-heterodyned hologram to sit on top of a second spatial-heterodyne carrier frequency defined by the second reference beam-object beam angle; applying a first digital filter to cut off signals around the first original origin and define a first result; performing a first inverse Fourier transform on the first result; applying a second digital filter to cut off signals around the second original origin and define a second result; and performing a second inverse Fourier transform on the second result, wherein the first reference beam-object beam angle is not equal to the second reference beam-object beam angle and a single digital image includes both the first spatially-heterodyned hologram and the second spatially-heterodyned hologram.
Abstract:
The invention concerns a microscope which computes a complex three-dimensional representation of an object based on a series of recordings of the light wave derived from the object and the wave lighting up the object, the wave lighting up the object varying between two successive recordings. The microscope comprises an optical part for generating interference figures between a reference light wave and a light wave diffracted by the object under observation, sensors for digitising said interference figures, actuators acting on the optical system, and a computer receiving the digitised interference figures, controlling the actuators and equipped with memory and computing means enabling it to compute three-dimensional images based on the interference figures according to a principle similar to holography. The optical part enables to record on one surface of the sensors (118) the wave derived from the object (112) by measuring the interference figures produced by the reference beam (Fr) and the wave derived from the object. The phase difference between the illumination wave and the reference wave is controlled for the recording series. The mirror (109) enables to vary the direction of the object parallel illuminating beam. The invention is applicable to biological, metrological or optical memory reading microscopy.
Abstract:
Holographic data in the form of electronic signals are generated through the utilization of two planar transparent supports (32) between which is positioned in region (33) an electro-optical dipolar medium which is normally opaque but light transmissive in the presence of an applied electric field. Orthogonally disposed arrays of transparent electrodes are positioned upon the transparent supports and are arranged to be sequentially scanned in sampling fashion to define a sequence of uniform electric fields forming apertures of consistent effective width. One of the surface of the supports receives the interference pattern generated by the reference and object illumination emanating from a coherent source and the opposite support is operatively associated with a photodetecting arrangement. Through the generation of scanning synchronization signals from master clock (58) and data signals from the photodetectors, an electronic representation of holographic data is achieved. To reconstruct these data, the same form of support (74) and normally opaque dipolar medium is employed in conjuction with a control scanning arrangement (84) wherein electrical fields corresponding with interference pattern intensity are provided. This arrangement may be utilized in conjunction with a reference beam of coherent light (80) to derive a virtual image (24') corresponding with the initially constructed holographic data.
Abstract:
An embodiment of the disclosed DHM system includes a com¬ mon-path in-line dual-plane DHM (160) comprising a light source (102) configured to emit coherent optical waves and further arranged to illuminate a specimen in an object area (112), a first optical Fouri¬ er element (LI, 162) configured to Fourier transform the optical waves from the object area, wherein the Fourier transform occurs at a Fouri¬ er plane and the optical waves from the object area includes direct¬ ly transmitted waves and diffracted waves, a phase modulator (164) at the Fourier plane configured to introduce a phase delay between the directly transmitted waves and the diffracted waves, a second optical Fourier element (L2, 166) configured to receive the directly transmitted waves and the diffracted waves from the phase modula¬ tor and to inversely Fourier transform the directly transmitted waves and the diffracted waves to provide interfered optical waves, at least one imaging device (CCD1, CCD2, 170,171) configured to record the interfered optical waves at two image planes (PI, P2) to generate a first interferogram and a second interferogram, and a computing de¬ vice (126) configured to compute specimen information using the in- terferograms.