Results 191 to 200 of about 132,566 (239)
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Hololens in speckle and speckle shear interferometry
Applied Optics, 1985This paper presents a number of methods to obtain in-plane displacement, out of plane displacement and slope data using holographic optical elements. The results obtained with a hololens and a holoshear lens are as good as those obtained with conventional optical systems.
C, Joenathan, R K, Mohanty, R S, Sirohi
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Speckle Imaging And Speckle Spectroscopy
SPIE Proceedings, 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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Optics Letters, 2015
A novel spectrometer concept is analyzed and experimentally verified. The method relies on probing the speckle displacement due to a change in the incident wavelength. A rough surface is illuminated at an oblique angle, and the peak position of the covariance between the speckle patterns observed in the far field with the two wavelengths reveals the ...
Maumita, Chakrabarti +2 more
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A novel spectrometer concept is analyzed and experimentally verified. The method relies on probing the speckle displacement due to a change in the incident wavelength. A rough surface is illuminated at an oblique angle, and the peak position of the covariance between the speckle patterns observed in the far field with the two wavelengths reveals the ...
Maumita, Chakrabarti +2 more
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Clinical and Experimental Dermatology, 1990
We report a case of a localized speckled compound naevus arising within normally pigmented skin. Speckled melanocytic naevi are reviewed and the distinctive features of the case enumerated.
A J, Carmichael, C Y, Tan
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We report a case of a localized speckled compound naevus arising within normally pigmented skin. Speckled melanocytic naevi are reviewed and the distinctive features of the case enumerated.
A J, Carmichael, C Y, Tan
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Subfeature speckle interferometry
Optics Letters, 1995A novel speckle technique, subfeature speckle interferometry, is introduced that relies on the amplitude interference of two independent speckle patterns, originating from coherent illumination, by use of an optical system that produces interferometric quality interference fringes on a scale comparable with the speckle correlation length.
D, Burckel +4 more
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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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Applied Optics, 1986
A computer-based method is developed to measure the out-of-plane motion of a surface which might arise, for example, from the deflection of a structural component or as a result of contouring a 3-D surface with respect to a reference plane. Artificial speckles are projected onto the test surface using an ordinary 35-mm projector equipped with a clear ...
J A, Gilbert +3 more
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A computer-based method is developed to measure the out-of-plane motion of a surface which might arise, for example, from the deflection of a structural component or as a result of contouring a 3-D surface with respect to a reference plane. Artificial speckles are projected onto the test surface using an ordinary 35-mm projector equipped with a clear ...
J A, Gilbert +3 more
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Physics in Medicine and Biology, 1989
It is demonstrated that the instantaneous frequency of a backscattered echo sequence can be used to pinpoint the location of destructive interference effects. These interference artefacts, which are generally interpreted as speckle in the image, are generally removed by stochastic averaging or filtering methods applied to the acquired image. The method
J C, Gatenby, J C, Hoddinott, S, Leeman
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It is demonstrated that the instantaneous frequency of a backscattered echo sequence can be used to pinpoint the location of destructive interference effects. These interference artefacts, which are generally interpreted as speckle in the image, are generally removed by stochastic averaging or filtering methods applied to the acquired image. The method
J C, Gatenby, J C, Hoddinott, S, Leeman
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Optics Letters, 1997
We report on a new laser feedback mechanism that uses speckle-pattern phenomena to create highly dispersive feedback. This speckle mirror is capable of creating laser emission as narrow as that from laser cavities using a number of dispersive elements such as gratings and prisms.
P C, de Oliveira +2 more
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We report on a new laser feedback mechanism that uses speckle-pattern phenomena to create highly dispersive feedback. This speckle mirror is capable of creating laser emission as narrow as that from laser cavities using a number of dispersive elements such as gratings and prisms.
P C, de Oliveira +2 more
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