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Speckle imaging

About: Speckle imaging is a research topic. Over the lifetime, 3730 publications have been published within this topic receiving 62354 citations.


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Journal ArticleDOI
TL;DR: It is demonstrated that under suitable conditions, it is possible to perform imaging to reconstruct the complex amplitude of objects situated at different depths and to retrieve the interference fringes projected behind the scattering medium.
Abstract: Optical imaging through complex scattering media is one of the major technical challenges with important applications in many research fields, ranging from biomedical imaging to astronomical telescopy to spatially multiplexed optical communications. Various approaches for imaging through a turbid layer have been recently proposed that exploit the advantage of object information encoded in correlations of the random optical fields. Here we propose and experimentally demonstrate an alternative approach for single-shot imaging of objects hidden behind an opaque scattering layer. The proposed technique relies on retrieving the interference fringes projected behind the scattering medium, which leads to complex field reconstruction, from far-field laser speckle interferometry with two-point intensity correlation measurement. We demonstrate that under suitable conditions, it is possible to perform imaging to reconstruct the complex amplitude of objects situated at different depths.

28 citations

Journal ArticleDOI
TL;DR: A recognizable diffraction-limited version of the true image of the object results, even when the imaging instrument is defocused such that, under perfect seeing conditions, the Airy disk is spread over an area comparable with that covered by a typical speckle image.
Abstract: Speckle images of spatially incoherent objects viewed under severe seeing conditions are formed in the optical laboratory (organized for simulations of stellar speckle interferometry). The brightest pixel in each speckle image is shifted to the center of image space, and the translated image is added to all other speckle images that have been similarly processed. A recognizable diffraction-limited version of the true image of the object results, even when the imaging instrument is defocused such that, under perfect seeing conditions, the Airy disk is spread over an area comparable with that covered by a typical speckle image.

28 citations

Journal ArticleDOI
TL;DR: The decrease in redundancy resulting from apodizing the telescope pupil results in an enhancement of the quality of reconstructed images at high light levels, which is particularly valuable when short-term variations in the statistics of the atmosphere make the seeing calibration of speckle interferograms difficult.
Abstract: The utility of partially redundant pupil geometries has been studied in the context of near-infrared speckle imaging with ground-based telescopes. Using both numerical simulations and experimental data collected with a 4-m-class telescope, we find that the decrease in redundancy resulting from apodizing the telescope pupil results in an enhancement of the quality of reconstructed images at high light levels. This improvement in imaging fidelity is particularly valuable when short-term variations in the statistics of the atmosphere make the seeing calibration of speckle interferograms difficult. However, the use of an apodizing mask necessarily restricts the faintest source that can be imaged, leading to a loss in sensitivity of one to two magnitudes. For many of the brighter near-infrared astrophysical sources in the sky that have been the subject of previous speckle-imaging studies, the use of a partially redundant pupil is expected to enhance the fidelity of the imaging procedure considerably.

28 citations

Journal ArticleDOI
TL;DR: A computerized system that permits automatic data reduction by introducing carrier fringes through the translation of a diverging lens is reported on.
Abstract: The introduction of a pulsed laser into an electronic speckle-shearing pattern interferometer allows high-speed transient deformations to be measured. We report on a computerized system that permits automatic data reduction by introducing carrier fringes through the translation of a diverging lens. The quantitative determination of the phase map that is due to deformation is carried out by the spatial synchronous detection method. Experimental results obtained for a metal plate transiently deformed by an electromagnetic hammer illustrate the advantages of the proposed system.

28 citations

Journal ArticleDOI
TL;DR: In this paper, an analysis of the effects of photon noise on astronomical speckle image reconstruction using the Knox-Thompson algorithm is presented, and it is shown that the quantities resulting from the average arre biased, but that the biases are easily estimated and compensated.

28 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202332
202249
202162
202079
201972
201895