Statistical properties of dynamic speckles

Yoshimura, Tsutomu

doi:10.1364/josaa.3.001032

Cited by 115 publications

(57 citation statements)

References 66 publications

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“…The corresponding f-number (f/#) is the focal length f divided by the radius q of the aperture. The speckle size r s on the CCD is then equal to [20]:…”

Section: Experiments and Resultsmentioning

confidence: 99%

Laser speckle imaging with an active noise reduction scheme

Völker¹,

Zakharov²,

Weber³

et al. 2005

Opt. Express

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Abstract:We present an optical scheme to actively suppress statistical noise in Laser Speckle Imaging (LSI). This is achieved by illuminating the object surface through a diffuser. Slow rotation of the diffuser leads to statistically independent surface speckles on time scales that can be selected by the rotation speed. Active suppression of statistical noise is achieved by accumulating data over time. We present experimental data on speckle contrast and noise for a dynamically homogenous and a heterogeneous object made from Teflon. We show experimentally that for our scheme spatial and temporal averaging provide the same statistical weight to reduce the noise in LSI: The standard deviation of the speckle contrast value scales with the effective number N of independent speckle as 1/ N . Phys. Rev. B 40, 9342-9345 (1989). 14. T. Yoshimura, and K. Fujiwara, "Statistical properties of doubly scattered image speckle," J. Opt. Soc. Am.A 9, 91-95 (1992). 15. D. J. Pine, D. A. Weitz, P. M. Chaikin, and E. Herbolzheimer, "Diffusing-wave spectroscopy," Phys. Rev.Lett. 60, 1134-1137 (1988). 16. L. Cipelletti, and D. A. Weitz, "Ultralow-angle dynamic light scattering with a charge coupled device camera based multispeckle, multitau correlator," Rev. Sci. Instrum. 70, 3214-3221 (1999).

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“…The corresponding f-number (f/#) is the focal length f divided by the radius q of the aperture. The speckle size r s on the CCD is then equal to [20]:…”

Section: Experiments and Resultsmentioning

confidence: 99%

Laser speckle imaging with an active noise reduction scheme

Völker¹,

Zakharov²,

Weber³

et al. 2005

Opt. Express

View full text Add to dashboard Cite

show abstract

“…In the camera plane, ω corresponds to the minimal speckle size, and τ C to the time it takes to "replace" a speckle pattern with an uncorrelated pattern. Yoshimura [25] gave an extensive overview of statistical properties of dynamic speckle patterns in different imaging geometries, demonstrating (again) an inverse relation between τ C and V, but proportionality was highly dependent on the exact experimental layout. Imaging a speckle pattern on a camera, yields V = r s /Mτ C , where r s is the speckle size in the object plane and M is the magnification of the imaging system.…”

Section: Relation Between τ C and Vmentioning

confidence: 98%

Quantitative laser speckle flowmetry of the in vivo microcirculation using sidestream dark field microscopy

Nadort

Woolthuis

Leeuwen

et al. 2013

Biomed. Opt. Express

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Abstract:We present integrated Laser Speckle Contrast Imaging (LSCI) and Sidestream Dark Field (SDF) flowmetry to provide real-time, noninvasive and quantitative measurements of speckle decorrelation times related to microcirculatory flow. Using a multi exposure acquisition scheme, precise speckle decorrelation times were obtained. Applying SDF-LSCI in vitro and in vivo allows direct comparison between speckle contrast decorrelation and flow velocities, while imaging the phantom and microcirculation architecture. This resulted in a novel analysis approach that distinguishes decorrelation due to flow from other additive decorrelation sources.

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“…The contribution due to translational flow motion can be represented as [11]: Green's function of the optical system used. The current formalism assumes the single scattering regime, that the number of particles in the scattering volume is large, that the conditions for a fully developed speckle pattern are met [17,18], and that the scattering system is ergodic (i.e., ensemble averaging is assumed equal to the time averaging).…”

Section: Statistical Model Of Scattered Radiation In the Oct Fiber Enmentioning

confidence: 99%

“…It is well known that the coherent radiation scattered by particulate media gives rise to a speckle pattern [10] and that the speckle statistics are different in the free space vs the image plane of a given optical system [11]. Since OCT yields depth resolved measurements, it is important to get the solution of the scattering problem not only for the exact focal plane of the optical system used, but also in its vicinity, specifically within several Rayleigh ranges of it.…”

Section: Introductionmentioning

confidence: 99%

Statistical properties of dynamic speckles from flowing Brownian scatterers in the vicinity of the image plane in optical coherence tomography

Popov¹,

Weatherbee²,

Vitkin³

2017

Biomed. Opt. Express

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Abstract:A closed-form analytical expression is obtained for the spatio-temporal correlation function of the scattered radiation detected in fiber-based optical coherence tomography (OCT), assuming a clean optical system arrangement in the OCT sample arm. It is shown that the transverse flow component causes purely translational speckle motion with the predicted speckle velocity 2x higher than the velocity of the flowing particles as would be observed in the image plane under incoherent illumination. It is also shown that both speckle velocity and speckle radius do not depend on the position of the scattering volume relative to the focal plane, hence the derived correlation function is independent of the position of the scattering volume relative to the focal plane. Although the analytical results are obtained for a clean optical system arrangement, they can be used with high accuracy in most practical implementations of fiber based OCT. Validation experiments in control scattering phantoms with varying liquid viscosities show excellent agreement with the developed theoretical model, under both no-flow and flow conditions. Accurate viscosity determinations enabled by this methodology may have applications to non-invasive glucose measurements in medicine.

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Statistical properties of dynamic speckles

Cited by 115 publications

References 66 publications

Laser speckle imaging with an active noise reduction scheme

Laser speckle imaging with an active noise reduction scheme

Quantitative laser speckle flowmetry of the in vivo microcirculation using sidestream dark field microscopy

Statistical properties of dynamic speckles from flowing Brownian scatterers in the vicinity of the image plane in optical coherence tomography

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