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    1. Mentioned In 63 Articles

    2. High-throughput dark-field full-field optical coherence tomography

      High-throughput dark-field full-field optical coherence tomography
      Full-field optical coherence tomography (FF-OCT) can rapidly acquire 2D en face OCT images through a scattering medium. However, the standard interferometer configurations waste almost 75% of light. In addition, specular reflections can saturate the detector, limiting FF-OCT performance. Here, we report on a high-throughput dark-field (HTDF) FF-OCT configuration that efficiently uses the available light budget and allows suppressing specular reflections. Specifically, we demonstrate that images acquired with the HTDF FF-OCT ...
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    3. High-resolution in-vivo human retinal imaging using full-field OCT with optical stabilization of axial motion

      High-resolution in-vivo human retinal imaging using full-field OCT with optical stabilization of axial motion
      Time-domain full-field OCT (FF-OCT) represents an imaging modality capable of recording high-speed en-face sections of a sample at a given depth. One of the biggest challenges to transfer this technique to image in-vivo human retina is the presence of continuous involuntary head and eye axial motion during image acquisition. In this paper, we demonstrate a solution to this problem by implementing an optical stabilization in an FF-OCT system. This was ...
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    4. Dynamic full-field optical coherence tomography: 3D live-imaging of retinal organoids

      Dynamic full-field optical coherence tomography: 3D live-imaging of retinal organoids
      Optical coherence tomography offers astounding opportunities to image the complex structure of living tissue, but lacks functional information. We present dynamic full-field optical coherence tomography to image living human induced pluripotent stem cell-derived retinal organoids non-invasively. Colored images with an endogenous contrast linked to organelle motility are generated, with sub-micrometer spatial resolution and millisecond temporal resolution, opening an avenue to identify specific cell types in living tissue via their function.
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    5. Modeling of full-field optical coherence tomography in scattering media

      Modeling of full-field optical coherence tomography in scattering media
      We develop a model of full-field optical coherence tomography (FF-OCT) that includes a description of partial temporal and spatial coherence, together with a mean-field scattering theory going beyond the Born approximation. Based on explicit expressions of the FF-OCT signal, we discuss essential features of FF-OCT imaging, such as the influence of partial coherence on the optical transfer function, and on the decay of the signal with depth. We derive the ...
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      Mentions: ESPCI ParisTech
    6. Distortion matrix concept for deep imaging in optical coherence microscopy

      Distortion matrix concept for deep imaging in optical coherence microscopy
      In optical imaging, light propagation is affected by the inhomogeneities of the medium. Sample-induced aberrations and multiple scattering can strongly degrade the image resolution and contrast. Based on a dynamic correction of the incident and/or reflected wave-fronts, adaptive optics has been employed to compensate for those aberrations. However, it mainly applies to spatiallyinvariant aberrations or to thin aberrating layers. Here, we propose a global and non-invasive approach based on ...
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    7. Probing dynamic processes in the eye at multiple spatial and temporal scales with multimodal full field OCT

      Probing dynamic processes in the eye at multiple spatial and temporal scales with multimodal full field OCT
      We describe recent technological progress in multimodal en face full-field optical coherence tomography that has allowed detection of slow and fast dynamic processes in the eye. We show that by combining static, dynamic and fluorescence contrasts we can achieve label-free high-resolution imaging of the retina and anterior eye with temporal resolution from milliseconds to several hours, allowing us to probe biological activity at subcellular scales inside 3D bulk tissue. Our ...
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    8. In vivo imaging through the entire thickness of human cornea by full-field optical coherence tomography

      In vivo imaging through the entire thickness of human cornea by full-field optical coherence tomography
      Despite obvious improvements in visualization of the in vivo cornea through the faster imaging speeds and higher axial resolutions, cellular imaging stays unresolvable task for OCT, as en face viewing with a high lateral resolution is required. The latter is possible with FFOCT, a method that relies on a camera, moderate numerical aperture (NA) objectives and an incoherent light source to provide en face images with a micrometer-level resolution. Recently ...
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    9. In vivo high resolution human corneal imaging using full-field optical coherence tomography

      In vivo high resolution human corneal imaging using full-field optical coherence tomography
      We present the first full-field optical coherence tomography (FFOCT) device capable of in vivo imaging of the human cornea. We obtained images of the epithelial structures, Bowmans layer, sub-basal nerve plexus (SNP), anterior and posterior stromal keratocytes, stromal nerves, Descemets membrane and endothelial cells with visible nuclei. Images were acquired with a high lateral resolution of 1.7 m and relatively large field-of-view of 1.26 mm x 1.26 ...
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    10. The multiple scattering limit in optical microscopy

      The multiple scattering limit in optical microscopy
      Optical microscopy offers a unique insight of biological structures with a sub-micrometer resolution and a minimum invasiveness. However, the inhomogeneities of the specimen itself can induce multiple scattering of light and optical aberrations which limit the observation to depths close to the surface. To predict quantitatively the penetration depth in microscopy, we theoretically derive the single-to-multiple scattering ratio in reflection. From this key quantity, the multiple scattering limit is deduced ...
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    11. Cell Motility as Contrast Agent in Retinal Explant Imaging With Full-Field Optical Coherence Tomography

      Cell Motility as Contrast Agent in Retinal Explant Imaging With Full-Field Optical Coherence Tomography
      Purpose : To use cell motility as a contrast agent in retinal explants. Methods : Macaque and mouse retinal explants were imaged with high resolution full field optical coherence tomography (FFOCT) and dynamic FFOCT, coupled with fluorescence imaging. Results : Static and dynamic FFOCT create complementary contrast from different structures within a cell. When imaging in vitro samples, static FFOCT detects steep refractive index gradients to reveal stationary structures including fibers, vessels, collagen ...
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    12. Fast subsurface fingerprint imaging with full-field optical coherence tomography system equipped with a silicon camera

      Fast subsurface fingerprint imaging with full-field optical coherence tomography system equipped with a silicon camera
      Images recorded below the surface of a finger can have more details and be of higher quality than conventional surface fingerprint images. This is particularly true when the quality of the surface fingerprints is compromised by, for example, moisture or surface damage. However, there is an unmet need for a cost effective fingerprint sensor that could record high-quality images at sufficient depth below the surface and in short-enough time. To ...
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    13. Full-Field Optical Coherence Tomography as a Diagnosis Tool: Recent Progress with Multimodal Imaging

      Full-Field Optical Coherence Tomography as a Diagnosis Tool: Recent Progress with Multimodal Imaging
      Full-field optical coherence tomography (FF-OCT) is a variant of OCT that is able to register 2D en face views of scattering samples at a given depth. Thanks to its superior resolution, it can quickly reveal information similar to histology without the need to physically section the sample. Sensitivity and specificity levels of diagnosis performed with FF-OCT are 80% to 95% of the equivalent histological diagnosis performances and could therefore benefit ...
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    14. Extracting relevant information for cancer diagnosis from dynamic full field OCT through image processing and learning

      Extracting relevant information for cancer diagnosis from dynamic full field OCT through image processing and learning
      For a large number of cancer surgeries, the lack of reliable intraoperative diagnosis leads to reoperations or bad outcomes for the patients. To deliver better diagnosis, we developed Dynamic Full Field OCT (D-FFOCT) as a complement to FFOCT. FFOCT already presents interesting results for cancer diagnosis e.g. Mohs surgery and reaching 96% accuracy on prostate cancer. D-FFOCT accesses the dynamic processes of metabolism and gives new tools to diagnose ...
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    15. Retinal imaging with adaptive optics full-field OCT

      Retinal imaging with adaptive optics full-field OCT
      Adaptive optics full-filed OCT (FFOCT) with a transmissive liquid crystal spatial light modulator (LCSLM) as wavefront corrector is used without strict plane conjugation for low order aberrations corrections. We validated experimentally that FFOCT resolution is independent of aberrations and only reduce the signal level. A signal based sensorless algorithm was thus applied for wavefront distortion compensation. Image quality improvements by the wavefront sensorless control of the LCSLM were evaluated on ...
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  2. About ESPCI ParisTech

    ESPCI ParisTech

    ESPCI ParisTech is a major institution of higher education an internationally renowned research center, and a fertile ground of innovation for industry.  Founded by the City of Paris in 1882, for over a century the School has attracted leading scientific innovators like Nobel Prize laureates Pierre and Marie Curie, Paul Langevin, Frédéric Joliot-Curie, Pierre-Gilles de Gennes, and Georges Charpak, who continue to contribute to the institution’s international reputation.  The School’s culture of excellence remains as vibrant as ever. Fully 60% of graduates go on to complete a thesis and earn their PhD. The School’s teaching faculty and researchers are building tomorrow’s knowledge base, publishing an article a day in top international scientific journals ; inventing the industry of the future, filing for a patent every single week.  A model of excellence and an illustration of the "French exception", ESPCI ParisTech is a founding member of ParisTech, the Paris Institute of Science and Technology.  Also see Langevin Institute (L’institut Langevin).