Stellar speckle interferometry

Dainty, J. C.

doi:10.1007/bfb0111441

Cited by 96 publications

(127 citation statements)

References 31 publications

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“…A much more useful prediction can be obtained from Berry's idea that a wavefunction of a chaotic system can be described as a random superposition of plane waves of the same wavenumber but different propagating direction. 36,37 Random plane wave (RPW) modeling gives predictions for both correlation functions above 36,38,39 which agree with the perturbation theory results for the diffusive regime: 35,40 ψ =⇒ e −|r The ψ correlation should thus approach 0, and the ψ 2 correlation should approach 1 for large r ′ . Figures 4 and 5 display our results for the diffusive regime, and show good agreement with the RPW predictions, especially in the ψ correlation.…”

Section: Simple Statistics: Agreement With Rmt/rpwsupporting

confidence: 66%

Statistics of wave functions in disordered systems with applications to Coulomb blockade peak spacing

2005

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Despite considerable work on the energy-level and wavefunction statistics of disordered quantum systems, numerical studies of those statistics relevant for electron-electron interactions in mesoscopic systems have been lacking. We plug this gap by using a tight-binding model to study a wide variety of statistics for the twodimensional, disordered quantum system in the diffusive regime. Our results are in good agreement with random matrix theory (or its extensions) for simple statistics such as the probability distribution of energy levels or spatial correlation of a wavefunction. However, we see substantial disagreement in several statistics which involve both integrating over space and different energy levels, indicating that disordered systems are more complex than previously thought. These are exactly the quantities relevant to electron-electron interaction effects in quantum dots; in fact, we apply these results to the Coulomb blockade, where we find altered spacings between conductance peaks and wider spin distributions than traditionally expected.

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Section: Simple Statistics: Agreement With Rmt/rpwsupporting

confidence: 66%

Statistics of wave functions in disordered systems with applications to Coulomb blockade peak spacing

2005

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“…In the absence of movement (or for very short exposure time) there is no detectable fluctuation and the typical granular interference pattern, called speckle, has the same properties in the entire field of view. In the classical picture, summarized by Goodman in [9], the scattered field amplitudes are randomly distributed and consequently the intensity values follow a negative exponential distribution ( )…”

Section: Introductionmentioning

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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“…2). As shown in [12], the coherence function J J J(x 1 , x 2 ) is a weighted integral of a function M(η) that describes the illuminated area's shape at the scattering surface:…”

Section: Speckle Field Covariance and The Attenuation Maskmentioning

confidence: 99%

Markov speckle for efficient random bit generation

et al. 2012

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Optical speckle is commonly observed in measurements using coherent radiation. While lacking experimental validation, previous work has often assumed that speckle's random spatial pattern follows a Markov process. Here, we present a derivation and experimental confirmation of conditions under which this assumption holds true. We demonstrate that a detected speckle field can be designed to obey the first-order Markov property by using a Cauchy attenuation mask to modulate scattered light. Creating Markov speckle enables the development of more accurate and efficient image post-processing algorithms, with applications including improved de-noising, segmentation and super-resolution. To show its versatility, we use the Cauchy mask to maximize the entropy of a detected speckle field with fixed average speckle size, allowing cryptographic applications to extract a maximum number of useful random bits from speckle images.

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Stellar speckle interferometry

Cited by 96 publications

References 31 publications

Statistics of wave functions in disordered systems with applications to Coulomb blockade peak spacing

Statistics of wave functions in disordered systems with applications to Coulomb blockade peak spacing

Laser speckle imaging with an active noise reduction scheme

Markov speckle for efficient random bit generation

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