Results 261 to 270 of about 85,035 (307)
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Paired correlation speckles and speckle moire
Annual Meeting Optical Society of America, 1987The mechanism of moire specklegram is explained in theory by the concept of paired correlation speckles.
Duomin He, Zhishen Liu
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Speckle photography combined with speckle interferometry
Optics and Lasers in Engineering, 2004By combining speckle interferometry (SI) measurements with speckle photography, the fringe visibility can be kept high despite the presence of a large bulk or rotating motion of the object. This combined technique improves the usability and measuring range of both pulsed and phase-stepped SI-methods. This paper reviews the theory of fringe formation in
N.-E. Molin +3 more
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Laser eye safety: the implications of ordinary speckle statistics and of speckled-speckle statistics
Journal of the Optical Society of America, 1981The implications of speckle statistics on laser eye-safety considerations are evaluated. The concept of speckled speckle is introduced, and its statistics are shown to correspond to the K0 function. Speckled speckle is defined in terms of the retinal power density when the eye is viewing an optically rough surface that is illuminated by a laser beam ...
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Speckle Masking and Speckle Spectroscopy in Astronomy
Quantum Limited Imaging and Information Processing, 1989The atmosphere of the earth restricts the resolution of conventional astronomical imaging to about 1 arcsec. Much higher resolution can be obtained by speckle methods. The Knox-Thompson method and the speckle masking method (bispectrum or triple correlation processing) yield diffraction-limited images in spite of image degradation by the atmosphere and
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Speckle evaluation in laser display: From speckle contrast to speckle influence degree
Optics Communications, 2020Abstract Speckle contrast (SC) is universally used to evaluate speckle in laser display, which has virtues of briefness in calculating and definitude in physical meaning. But the results characterized by SC is usually inconsistent with human visual perception.
Yuan Yuan +6 more
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Use of low-coherence speckled speckles for bioflow measurements
Applied Optics, 2000Formation of speckled speckles in the case of biflow perfusion by partially coherent light was considered. Dependencies of statistical characteristics of low-coherence biospeckles with a small number of scatterers on the scattering properties of the flow and on the coherence length of incident light were analyzed.
S S, Ulyanov, V V, Tuchin
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Technique for the removal of speckle phase in electronic speckle interferometry
Optics Letters, 1995It is shown that the speckle nature of electronic speckle pattern interferometry images can be reduced in quasireal time with the use of only three consecutive video images. By use of additive-subtractive phase modulation processing the technique is essentially insensitive to environmental noise, and distortion of fringes does not occur.
B F, Pouet, S, Krishnaswamy
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Optimizing the parameters for measuring laser speckle and speckle contrast
Applied Optics, 2014Evaluating the contrast in speckle patterns produced by laser projection displays can facilitate the development of methods to suppress such imperfection. Computer simulations were first conducted to characterize the contrast (C(gs)) of fully developed speckle patterns with spatial factor k and power factor r.
Wei-Feng, Hsu, Min-Chun, Chou
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Applied Optics, 2019
The propagation of a coherent beam of light through a random scattering medium results in the generation of a speckle pattern. Although the intensity distribution of the speckle pattern is random in nature, the information of the object hidden behind a scattering medium is scrambled into it.
Abhijit Roy +2 more
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The propagation of a coherent beam of light through a random scattering medium results in the generation of a speckle pattern. Although the intensity distribution of the speckle pattern is random in nature, the information of the object hidden behind a scattering medium is scrambled into it.
Abhijit Roy +2 more
openaire +2 more sources