Abstract:
A method for lens-free imaging of a sample or objects within the sample uses multi-height iterative phase retrieval and rotational field transformations to perform wide FOV imaging of pathology samples with clinically comparable image quality to a benchtop lens-based microscope. The solution of the transport-of-intensity (TIE) equation is used as an initial guess in the phase recovery process to speed the image recovery process. The holographically reconstructed image can be digitally focused at any depth within the object FOV (after image capture) without the need for any focus adjustment, and is also digitally corrected for artifacts arising from uncontrolled tilting and height variations between the sample and sensor planes. In an alternative embodiment, a synthetic aperture approach is used with multi-angle iterative phase retrieval to perform wide FOV imaging of pathology samples and increase the effective numerical aperture of the image.
Abstract:
A method and system for use in reconstruction and retrieval of phase information associated with a two-dimensional diffractive response are presented. The method comprising: providing (75) input data indicative of one or more diffractive patterns corresponding to diffractive responses from one or more objects (50). Dividing (130) said input data into a plurality of one-dimensional slices and determining (140) one-dimensional phase data for at least some of said one-dimensional slices. Tailoring (150) the reconstructed phase data of said one-dimensional slices to form a two-dimensional phase solution. The two-dimensional phase solution is defined by phase shifts of said reconstructed one-dimensional phase data of said one-dimensional slices. The two-dimensional phase solution thus enables obtaining two-dimensional reconstructed phase data suitable for reconstruction of image data (250).
Abstract:
Methods and apparatus for imaging a phase or amplitude that characterizes a scattered field emanating from a physical medium. A local probe is stepped to a plurality of successive probe positions and illuminated with an illuminating beam, while a specified phase function is imposed on a reference beam relative to the illuminating beam. A field associated with the scattered field is superimposed with the reference beam and the detection of both yields a detected signal which is recorded as a function of probe position in order to obtain a hologram. The holograph is transformed, filtered, and retransformed to generate an image. Alternatively, the illuminating beam may directly illuminate successive positions of the physical medium.
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.
Abstract:
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.
Abstract:
Procédé d'observation d'un échantillon (10) comportant une étape d'illumination de l'échantillon par une source de lumière et l'enregistrement d'une pluralité d'images, par un photodetecteur(16), les images représentant la lumière transmise par l'échantillon dans différentes bandes spectrales. A partir de chaque image, on détermine une amplitude complexe représentative de l'onde lumineuse transmise par l'échantillon dans une bande spectrale déterminée. Le procédé, itératif, comprend alors : • - la rétropropagation de chaque amplitude complexe dans un plan de l'échantillon, • - le calcul d'une fonction de pondération à partir d'une somme pondérée des amplitudes complexes rétropropagées, • - la propagation de ladite fonction de pondération dans le plan du photodétecteur, • - la mise à jour de chaque amplitude complexe, dans le plan de l'échantillon, en fonction de la fonction de pondération ainsi propagée.
Abstract:
L'invention est un procédé pour identifier l'état d'une cellule (1, 2, 3, 4, 5) contenue dans un échantillon (14) comportant l'illumination de l'échantillon à l'aide d'une source de lumière (11), cette dernière produisant une onde lumineuse (12) incidente se propageant vers l'échantillon (14), puis l'acquisition, à l'aide d'un photodétecteur matriciel (16), d'une image de l'échantillon (14), l'échantillon (14) étant disposé entre ladite source de lumière (11) et le photodétecteur matriciel (16), de telle sorte que le photodétecteur matriciel (16) est exposé à une onde lumineuse (22) comprenant des interférences entre l'onde lumineuse incidente (12) et une onde de diffraction produite par chaque cellule (1, 2, 3, 4, 5). Le procédé est caractérisé en ce qu'il comporte l'application d'un algorithme de reconstruction numérique à l'image acquise par le photodétecteur matriciel (16), pour estimer une grandeur caractéristique de l'onde lumineuse parvenant au détecteur matriciel (16), à une pluralité de distances (z) du photodétecteur matriciel (16). La valeur de la grandeur caractéristique, ou son évolution en fonction de la distance (z) permettant de déterminer l'état de la cellule (1, 2, 3, 4, 5) parmi des états prédéterminés.
Abstract:
A method of imaging includes illuminating a sample spaced apart from an image sensor at a multiple distances. Image frames of the sample obtained at each distance are registered to one another and lost phase information from the registered higher resolution image frames is iteratively recovered. Amplitude and/or phase images of the sample are reconstructed based at least in part on the recovered lost phase information.
Abstract:
A system for imaging a cytological sample includes a sample holder configured to hold a cytological sample. A spatial filter is disposed at a distance z1 from the sample holder on first side of the sample holder, the spatial filter having an aperture disposed therein configured to allow the passage of illumination. An imaging sensor array is disposed at a distance z2 from the sample holder on a second, opposite side of the sample holder. An illumination source is configured to illuminate the cytological sample through the aperture, the spatial filter being interposed between the illumination source and the sample holder.