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  2. Speckle (interference) - Wikipedia

    en.wikipedia.org/wiki/Speckle_(interference)

    Speckle imaging and eye testing using speckle also use the speckle effect. Speckle is the chief limitation of coherent lidar and coherent imaging in optical heterodyne detection. In the case of near field speckles, the statistical properties depend on the light scattering distribution of a given sample.

  3. Laser speckle contrast imaging - Wikipedia

    en.wikipedia.org/wiki/Laser_speckle_contrast_imaging

    Laser speckle contrast imaging (LSCI), also called laser speckle imaging (LSI), is an imaging modality based on the analysis of the blurring effect of the speckle pattern. The operation of LSCI is having a wide-field illumination of a rough surface through a coherent light source.

  4. Speckle imaging - Wikipedia

    en.wikipedia.org/wiki/Speckle_imaging

    Slow-motion speckle imaging movie, showing how a high-magnification (negative) image of a star breaks up into multiple blobs (speckles), entirely an atmospheric effect. Speckle imaging comprises a range of high-resolution astronomical imaging techniques based on the analysis of large numbers of short exposures that freeze the variation of ...

  5. Eye testing using speckle - Wikipedia

    en.wikipedia.org/wiki/Eye_testing_using_speckle

    When a surface is illuminated by a laser beam and is viewed by an observer, a speckle pattern is formed on the retina. [ 2 ] [ 3 ] If the observer has perfect vision, the image of the surface is also formed on the retina, and movement of the head will result in the speckle pattern and the surface moving together so that the speckle pattern ...

  6. Speckle variance optical coherence tomography - Wikipedia

    en.wikipedia.org/wiki/Speckle_variance_optical...

    Speckle variance optical coherence tomography (SV-OCT) is an imaging algorithm for functional optical imaging. Optical coherence tomography is an imaging modality that uses low-coherence interferometry to obtain high resolution, depth-resolved volumetric images. OCT can be used to capture functional images of blood flow, a technique known as ...

  7. Lucky imaging - Wikipedia

    en.wikipedia.org/wiki/Lucky_imaging

    Lucky image of M15 core. Lucky imaging (also called lucky exposures) is one form of speckle imaging used for astrophotography.Speckle imaging techniques use a high-speed camera with exposure times short enough (100 ms or less) so that the changes in the Earth's atmosphere during the exposure are minimal.

  8. Optical heterodyne detection - Wikipedia

    en.wikipedia.org/wiki/Optical_heterodyne_detection

    Optical heterodyne detection is a method of extracting information encoded as modulation of the phase, frequency or both of electromagnetic radiation in the wavelength band of visible or infrared light. The light signal is compared with standard or reference light from a "local oscillator" (LO) that would have a fixed offset in frequency and ...

  9. Electronic speckle pattern interferometry - Wikipedia

    en.wikipedia.org/wiki/Electronic_speckle_pattern...

    Electronic speckle pattern interferometry (ESPI), [1] also known as TV holography, is a technique that uses laser light, together with video detection, recording and processing, to visualise static and dynamic displacements of components with optically rough surfaces. The visualisation is in the form of fringes on the image, where each fringe ...