Abstract:
An interferometric system and a method of measurement of refractive index spatial distribution for use in digital holographic microscopy to observe samples in reflected as well as transmitted radiation or to observe luminescent samples comprises a first branch and a second branch with a plurality of optical elements. The first branch comprises a diffraction grating located in a plane optically conjugated with the object plane in order to create an achromatic hologram with spatial carrier frequency in the output image plane.
Abstract:
A method for irradiating a medium includes irradiating the medium with an electromagnetic wave which is scattered in the medium and modulated in frequency at a position in the medium; obtaining information corresponding to an interference pattern generated by interference between the modulated electromagnetic wave and a reference wave; and generating a phase conjugate wave, based on the obtained information, which irradiates the medium.
Abstract:
Motility contrast imaging (MCI) is a depth-resolved holographic technique to extract cellular and subcellular motion inside tissue. The holographic basis of the measurement technique makes it highly susceptible to mechanical motion. The motility contrast application, in particular, preferably includes increased mechanical stability because the signal is based on time-varying changes caused by cellular motion, not to be confused with mechanical motion of the system. The use of the resulting spectrogram response signatures, or “fingerprint” data, of known compounds is disclosed to screen new compounds for leads as to those having potentially beneficial mechanisms of action. The “fingerprint” data of known toxic compounds can be used to screen new compounds for toxicity.
Abstract:
A device comprising an authentication hologram recorded within a defined volume of a holographic recording medium, wherein the authentication hologram is configured to convey authentication information; wherein the authentication hologram comprises a plurality of related volumetric holograms recorded within the defined volume; and wherein the holographic recording medium comprises an optically transparent plastic material and a photochemically active dye. In one embodiment, all the holograms are identical. In one embodiment, the holograms are different.
Abstract:
A method for sensing a wave-front of specimen light scattered from an illuminated area in a specimen (10) includes the steps of focusing illumination light into the specimen (10), directing specimen light scattered in the specimen (10) to a detector device (50) having a plurality of detector elements (51) and being capable to sense light with local resolution, detecting sample light contained in the specimen light with the detector device (50), said sample light being scattered in a predetermined sample plane (11) of the specimen (10) and being selected by a time-based gating of the specimen light, locally resolved measuring phase information of the sample light, and reconstructing the wave-front of the sample light on the basis of the phase information. Furthermore, a method of microscopic imaging with adapted illumination light is described.
Abstract:
A holographic imaging apparatus having a pulsed laser light source for generating an object beam and a reference beam whereby an object, obscured by a diffusing medium, is illuminated by the object beam. A real time interferogram recording medium is exposed to the coincidence of light reflected from the object and the reference beam to record an interferogram. A holographic image is then reconstructed from the interferogram and may be viewed and recorded. The pulsed laser light source generates a beam which is divided by a conventional beam splitter device into an object beam and a reference beam. The object beam is then diverged by a lens which forms a diverging object beam to illuminate the object. The reference beam is diverged through another lens to form a diverging reference beam which is directed so that it illuminates a photoreactive crystal. The coincidence of the reflected light and diverging reference beam generates a pattern of interference fringes known as an interferogram which is recorded by the crystal. The apparatus can use time-gating in the holographic medium to use ballistic and snake-like light, which arrives before scattered light, to construct a holographic image. The apparatus can also obtain depth information for 3-D images by using the time-gating technique to obtain the image bearing light from a 3-D object. The apparatus also may record light-in-flight images of the object, to record different depths of the object separately, by using an optical delay assembly.
Abstract:
A method of analyzing a sample receiving a particle of interest, including: defining a reference point located on a first interface of the sample, or at a known distance from the sample, along the optical axis of the optical system; acquiring a reference image transmission of the sample, the object plane of the optical system being located at a known distance from the reference point along an axis parallel to the optical axis of the optical system, and the particle of interest being located outside of the object plane; using the reference image, digitally constructing a series of reconstructed images, each associated with a predetermined offset of the object plane along the optical axis of the optical system; and using the series of reconstructed images, determining the distance along an axis parallel to the optical axis of the optical system, between the particle of interest and the reference point.
Abstract:
The invention relates to a method and arrangement for short coherence holography for distance measurement, for profile detection and/or for 3D detection of one or more object elements and/or object areas and/or objects or for readout of holographic volume memories with a holographic interferometer and with at least one short coherence light source. For each optically detected object element in the hologram the holographic interferometer has an optical path difference clearly unequal to zero. At least one spectrally integrally detecting, rastered detector is arranged. The short coherence light source with frequency comb is designed with the optical delay length Y1. Detected holograms are digitally reconstructed. Relative distances of object elements are digitally calculated from the hologram reconstructions, so that a 3D point cloud of object elements and/or object areas and/or objects is produced. Data can be read out optically in parallelized form from holographic volume memories or three-dimensionally structured signatures.
Abstract:
A system for motility contrast imaging a biological target within tissue comprising a CCD array; an illumination source for generating an incoming beam; a first beam splitter for receiving the incoming beam and producing an object beam and a reference beam; a second beam splitter for illuminating a multitude of biological targets with the object beam and for directing backscattered object beams towards the CCD array; a computer-controlled delay stage for zero-path-matching the reference beam to the backscattered object beams; a reference beam that intersects the backscattered object beams at an angle to produce a series of interference fringes that modulate Fourier-domain information; and a computer for receiving a time series of Fourier-domain information. The interference fringes between the backscattered object beam and the reference beam are recorded by the CCD array and passed to the computer which constructs a digital hologram at successive times.
Abstract:
An apparatus includes a light source configured to emit an electromagnetic wave; a spatial light modulator configured to modulate a wavefront of the electromagnetic wave to irradiate a sample; a plate with an aperture; a lens unit configured to set a focal point in the sample; a detector configured to detect light coming from the focal point of the sample through the aperture; and a controller configured to control the spatial light modulator based on the detected light by the detector.