153 results about "Digital holographic microscopy" patented technology

A new way of mixing instrumental and digital means is described for the general field of wave front sensing. The present invention describes the use, the definition and the utility of digital operators, called digital wave front operators (DWFO) or digital lenses (DL), specifically designed for the digital processing of wave fronts defined in amplitude and phase. DWFO are of particular interest for correcting undesired wave front deformations induced by instrumental defects or experimental errors. DWFO may be defined using a mathematical model, e.g. a polynomial function, which involves coefficients. The present invention describes automated and semi-automated procedures for calibrating or adjusting the values of these coefficients. These procedures are based on the fitting of mathematical models on reference data extracted from specific regions of a wave front called reference areas, which are characterized by the fact that specimen contributions are a priori known in reference areas. For example, reference areas can be defined in regions where flat surfaces of a specimen produce a constant phase function. The present invention describes also how DWFO can be defined by extracting reference data along one-dimensional (1D) profiles. DWFO can also be defined in order to obtain a flattened representation of non-flat area of a specimen. Several DWFO or DL can be combined, possibly in addition with procedures for calculating numerically the propagation of wave fronts. A DWFO may also be defined experimentally, e.g. by calibration procedures using reference specimens. A method for generating a DWFO by filtering in the Fourier plane is also described. All wave front sensing techniques may benefit from the present invention. The case of a wave front sensor based on digital holography, e.g. a digital holographic microscope (DHM), is described in more details. The use of DWFO improves the performance, in particular speed and precision, and the ease of use of instruments for wave front sensing. The use of DWFO results in instrumental simplifications, costs reductions, and enlarged the field of applications. The present invention defines a new technique for imaging and metrology with a large field of applications in material and life sciences, for research and industrial applications.

The present invention is related to a compact microscope able to work in digital holography for obtaining high quality 3D images of samples, including fluorescent samples and relatively thick samples such as biological samples, said microscope comprising illumination means (1,41) at least partially spatially coherent for illuminating a sample (2) to be studied and a differential interferometer (5) for generating interfering beams from said sample (2) on the sensor (33) of an electronic imaging device (7), said interferometer (5) comprising namely tilting means (17) for tilting by a defined angle one the interfering beams (28 or 29) relatively to the other, said tilting resulting into a defined shift (27) of said interfering beam on the sensor of the electronic imaging device (7), said shift (27) being smaller than spatial coherence width of each beam, said microscope being able to be quasi totally preadjusted independently from the samples so that minimum additional adjustments are required for obtaining reliable 3D images of samples.

A method and device for obtaining a sample with three-dimensional microscopy, in particular a thick biological sample and the fluorescence field emitted by the sample. One embodiment includes obtaining interferometric signals of a specimen, obtaining fluorescence signals emanating from the specimen, recording these signals, and processing these signals so as to reconstruct three-dimensional images of the specimen and of the field of fluorescence emitted by the specimen at a given time. Another embodiment includes a digital holography microscope, a fluorescence excitation source illuminating a specimen, where the microscope and the fluorescence excitation source cooperate to obtain interferometric signals of the specimen and obtain fluorescence signals emanating from the specimen, means for recording the interferometric signals and fluorescence signals, and means for processing the interferometric signals and the fluorescence signals so as to reconstruct three-dimensional images of the specimen and of the field of fluorescence emitted by the specimen at a given time.

An Interferometer for off-axis digital holographic microscopy includes a recording plane, and a grating located in a plane optically conjugated with the recording plane. The grating defining a first and a second optical path, the optical path corresponding to different diffraction order.

The present invention discloses a method to improve the image resolution of a microscope. This improvement is based on the mathematical processing of the complex field computed from the measurements with a microscope of the wave emitted or scattered by the specimen. This wave is, in a preferred embodiment, electromagnetic or optical for an optical microscope, but can be also of different kind like acoustical or matter waves. The disclosed invention makes use of the quantitative phase microscopy techniques known in the sate of the art or to be invented. In a preferred embodiment, the complex field provided by Digital Holographic Microscopy (DHM), but any kind of microscopy derived from quantitative phase microscopy: modified DIC, Shack-Hartmann wavefront analyzer or any analyzer derived from a similar principle, such as multi-level lateral shearing interferometers or common-path interferometers, or devices that convert stacks of intensity images (transport if intensity techniques: TIT) into quantitative phase image can be used, provided that they deliver a comprehensive measure of the complex scattered wavefield. The hereby-disclosed method delivers superresolution microscopic images of the specimen, i.e. images with a resolution beyond the Rayleigh limit of the microscope. It is shown that the limit of resolution with coherent illumination can be improved by a factor of 6 at least. It is taught that the gain in resolution arises from the mathematical digital processing of the phase as well as of the amplitude of the complex field scattered by the observed specimen. In a first embodiment, the invention teaches how the experimental observation of systematically occurring phase singularities in phase imaging of sub-Rayleigh distanced objects can be exploited to relate the locus of the phase singularities to the sub-Rayleigh distance of point sources, not resolved in usual diffraction limited microscopy. In a second, preferred embodiment, the disclosed method teaches how the image resolution is improved by complex deconvolution. Accessing the object's scattered complex field—containing the information coded in the phase—and deconvolving it with the reconstructed complex transfer function (CTF) is at the basis of the disclosed method. In a third, preferred embodiment, it is taught how the concept of “Synthetic Coherent Transfer Function” (SCTF), based on Debye scalar or Vector model includes experimental parameters of MO and how the experimental Amplitude Point Spread Functions (APSF) are used for the SCTF determination. It is also taught how to derive APSF from the measurement of the complex field scattered by a nanohole in a metallic film. In a fourth embodiment, the invention teaches how the limit of resolution can be extended to a limit of λ/6 or smaller based angular scanning. In a fifth embodiment, the invention teaches how the presented method can generalized to a tomographic approach that ultimately results in super-resolved 3D refractive index reconstruction.

The present invention provides for a digital holographic microscope using a holographic interferometer and incorporating a TIR sample mount and microscopic imaging optics. The microscope uses phase shifting from frustrated internal reflection within a prism to measure nanometric distances. The invention also provides for a numerical reconstruction algorithm of an inclined surface of the object/prism.

The invention relates to a physical parameter common-channel phase-shift digital holographic microscopic device based on a diffraction grating, which comprises a lighting unit, a microscopic unit, an interference generating unit and an imaging unit, wherein the lighting unit and the microscopic unit are respectively arranged at two sides of a sample; the lighting unit comprises a laser and a light intensity controller arranged in front of the laser; the microscopic unit comprises a second telescope unit which consists of a microobjective and a third lens; the sample is placed on the front focal plane of the second telescope unit; the interference generating unit comprises a beam splitting unit, a filtering unit, a beam combining unit and a contrast control unit sequentially arranged in the light path direction; and the imaging unit comprises a CCD (charge coupled device) camera which is arranged on the rear focal plane of a seventh lens. The digital holographic microscopic device has the advantages of good stability and no sensitivity to ambient vibration.

An interferometric method for detecting information about a sample includes emitting a laser beam; splitting the laser beam into a reference beam and an object beam; transmitting the object beam through the sample in an incident angle; combining the reference beam with the object beam passed through the sample to form an interference pattern; detecting the interference pattern, and non-linearly scanning the object beam in order to detect a plurality of interference patterns.

A method and system for performing three-dimensional holographic microscopy of an optically trapped one dimensional structure. The method and system use an inverted optical microscope, a laser source which generates a trapping laser beam wherein the laser beam is focused by an objective lens into a plurality of optical traps. The method and system also use a collimated laser at an imaging wavelength to illuminate the structure created by the optical traps. Imaging light scattered by the optically tapped structure forms normalized intensity holograms that are imaged by a video camera and analyzed by optical formalisms to determine light field to reconstruct 3-D images for analysis and evaluation.

A non-destructive method and device for analyzing a sample comprising transparent living and/or dead cells, by 5 means of a digital holographic microscope, where the sample (8) is exposed to light from a laser (2). The light that travels through the cells in the sample will experience a difference in the optical path length compared to the surrounding media and the wave front that emerges from the 10 cells will thus be phase shifted. This distortion can be detected in the digital hologram, which is reconstructed from the interference pattern detected by a digital sensor (17), such as a CCD or a CMOS, as phase differences or phase shifts and thereby creating a digital hologram. The 15 phase shift of each element of the hologram is then used for analyzing the characteristics of the cells in the sample.

The invention discloses an inverted digital holographic microscope, which belongs to the digital holographic technical field, and can be used for three-dimensional real-time appearance measurement and biological cell imaging. In the inverted digital holographic microscope, an optical fiber coupler 4 is arranged in front of a laser 5 and connected with an optical fiber beam splitter 3 through an optical fiber; the optical fiber beam splitter 3 is connected with two paths of optical fibers respectively connected with an optical fiber collimator 1 and an optical fiber collimator 6, a sample stage 11 for placing a sample 13 is arranged under the optical fiber collimator 1, and the sample stage 11 is connected with a two-dimensional translation stage 12; a micro objective mounted on a one-dimensional translation stage 10 is located under the sample stage 11, and the micro objective 9 and the optical fiber collimator 6 are aligned with two mutually vertical sides of a beam combination crystal 8; and a CCD (charge-coupled device) camera 7 is located under the beam combination crystal 8. The inverted digital holographic microscope can be used for observing the living cell which is located at the bottom of a culture dish and grows along a wall of the culture dish with a high resolution ratio for long time, and is highly integrated and small in volume; moreover, with the optical fiber connection, the laser can be freely mounted on other parts of the system.

An embodiment of the disclosed DHM system includes a light source configured to emit coherent optical waves, a first optical Fourier element configured to Fourier transform the optical waves from the object area, wherein the Fourier transform occurs at a Fourier plane and the optical waves from the object area includes directly transmitted waves and diffracted waves, a phase modulator at the Fourier plane configured to introduce a phase delay between the directly transmitted waves and the diffracted waves, a second optical Fourier element configured to receive the directly transmitted waves and the diffracted waves from the phase modulator and to inversely Fourier transform the directly transmitted waves and the diffracted waves to provide interfered optical waves, and at least one imaging device configured to record the interfered optical waves at two image planes to generate a first interferogram and a second interferogram.

The invention relates to a digital holographic microscopy measuring device. It includes a laser beam splitting system which is connected with a digital microscopic image register system via a holographic microscopy system, said digital holographic microscopy system comprises object light transmission path, reference light transmission path and digital holographic image register system , the output of holographic microscopy system is connected with a object microscopic image visual system. The invention can realize the configuration measurement and the deformation detection of transparent microscopic object, and monitor the shape change of transparent microscopic object, the visual and digital recording of the microscopic image are also realized. The device can realize the non-contacting gauge of transparent substance fine texture which is based on the digital holographic microscopy; the dynamic property is well, substance to be measured don't need preparation of fluorescence and section.

The invention discloses a reflection-type off-axis digital holographic microscopy measurement device, which comprises a light source unit, an object light adjusting unit, a reference light adjusting unit and an image processing unit. The reference light adjusting unit comprises an optical path adjustment reflector group and an optical path guidance reflector group. The optical path adjustment reflector group comprises a first reflector and a second reflector, the positions of which are relatively fixed. The first reflector is used for reflecting the reference light R to the second reflector; the second reflector is used for reflecting the input reference light R to the optical path guidance reflector group; the optical path of the reference light R can be adjusted by moving the optical path adjustment reflector group wholly; the optical path guidance reflector group can guide the reference light R, the optical path of which is adjusted, to be input to the image processing unit to have interference with reflected light O'; and the image processing unit is used for processing interference fringes to obtain a sample three-dimensional image. The device can improve the quality of the holographic image.

The invention discloses a three-dimensional micro-observation apparatus for a smooth reflective surface and the apparatus is based on synthetic aperture in digital holography. The apparatus comprises a light source, light splitting unit, space filters, plano-convex lenses, a planar mirror, a depolarization beam splitter prism, a beam adjuster, a rotating stage and a complementary metal-oxide semiconductor (CMOS) camera. A light path of the apparatus is characterized in that: a laser emitted by the light source is incident to the light splitting unit; after a light splitting processing is carried out by the light splitting unit, illuminating light and reference light are output; two beams of light respectively pass through the space filters and the plano-convex lenses in order so as to be processed by beam expansion and shaping; the illuminating light passes through the planar mirror and outputs parallel light that penetrates the depolarization beam splitter prism and is incident inclinedly to a surface of an observed object on the rotating stage; and then reflected light of the object surface is again incident to the depolarization beam splitter prism; an angle and a position of the reference light are adjusted by the beam adjuster and the reference light is also incident to the depolarization beam splitter prism; and light composition processing is carried out on the incidentreference light and an object light by the depolarization beam splitter prism so as to obtain a combined light beam; and an interference hologram formed by the combined light beam is captured by a photosensitive surface of the CMOS camera. During the obtaining process, the rotating stage is rotated and an incident angle of the illuminating light is adjusted many times, so that an object surface hologram that contains different frequency components is obtained; and then fusion is carried out, thereby realizing a three-dimensional micro-observation based on the synthetic aperture in digital holography.

A method for analyzing digital holographic microscopy (DHM) data for hematology applications includes receiving a plurality of DHM images acquired using a digital holographic microscopy system. One or more connected components are identified in each of the plurality of DHM images and one or more training white blood cell images are generated from the one or more connected components. A classifier is trained to identify a plurality of white blood cell types using the one or more training white blood cell images. The classifier may be applied to a new white blood cell image to determine a plurality of probability values, each respective probability value corresponding to one of the plurality of white blood cell types. The new white blood cell image and the plurality of probability values may then be presented in a graphical user interface.

The invention, which belongs to the field of digital holographic microscopy (DHM), relates to a digital holographic microscopy device based on local hollow beam illumination and a working method thereof. The digital holographic microscopy device is composed of a laser device, an optical beam splitter I, an optical beam splitter II, an optical reflector I, an optical reflector II, a dark field condenser, a microscope objective I, a microscope objective II, a spatial filter, a first lens L1, a second lens L2, a third lens L3, a computer, and other components. The digital holographic microscopy device is implemented as follows: after incidence of a generated local hollow light beam to the dark field condenser, an annular light cone illumination experiment sample is formed; with the digital holography, interference fringes of diffracted light and reference light of the sample are recorded to the computer by an optocoupler device; and then on the basis of a reconstructive technique, a three-dimensional image of an object is reproduced. Compared with the traditional digital holographic microscopy, the digital holographic microscopy device provided by the invention has the higher resolution and contrast ratio and is suitable for microcosmic fields such as observation of living cells and solvent particles in biomedical detection.

The invention discloses a pulse laser-based reflective digital holographic microscopy imaging system and method. The reflective digital holographic microscopy imaging system comprises an optical imaging sub system and a synchronous control sub system for controlling the operation of the optical imaging sub system, wherein the optical imaging sub system comprises a pulse laser, a laser attenuator, a steering apparatus, a light beam transfer apparatus and a holographic imaging apparatus which are arranged in sequence; the synchronous control sub system comprises an industrial control host and a synchronous controller; the reflective digital holographic microscopy imaging method comprises the following steps of 1, establishing the holographic microscopy imaging system; 2, performing synchronous control on the pulse laser and a digital camera; 3, obtaining hologram data; and 4, performing three-dimensional appearance holographic image display on the surface of a test sample. The system and the method are creative in design; by performing synchronous control on the pulse laser and the digital camera, the high-frequency micro-vibration test sample hologram is obtained; light path interference is completed through four beam splitters, so that a condition that reflective stray light enters the hologram caused by self parts in the light path can be avoided; and the hologram is high in quality.