Results 91 to 100 of about 1,594 (137)
Some of the next articles are maybe not open access.
Optics & Laser Technology, 1984
Abstract A number of speckle shear methods and their applications to ndt are discussed. Experiments using multiple apertures with custom-made optical elements have shown that in-plane displacement, slope and curvature patterns can be obtained by filtering through appropriate haloes.
openaire +1 more source
Abstract A number of speckle shear methods and their applications to ndt are discussed. Experiments using multiple apertures with custom-made optical elements have shown that in-plane displacement, slope and curvature patterns can be obtained by filtering through appropriate haloes.
openaire +1 more source
Heterodyne temporal speckle-pattern interferometry
Applied Optics, 2000In temporal speckle-pattern interferometry deformation information is extracted by a Fourier transform technique from the speckle pattern that is recorded over a period of time as the object is deformed. A limitation of the experimental arrangements reported to date is that the direction of the deformation cannot be determined. We propose removing this
P, Haible, M P, Kothiyal, H J, Tiziani
openaire +2 more sources
Speckle interferometry in transparent media
Applied Optics, 1986Speckle interferometry is applied to transparent media to obtain measurements of full-field density variations. Speckle interferometry can present decreased vibration sensitivity compared to some wave front comparison methods while maintaining high sensitivity.
D D, Verhoeven, P V, Farrell
openaire +2 more sources
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
openaire +1 more source
Computer-aided speckle pattern interferometry
Applied Optics, 1983An on-line computer system for measuring the deformation of a diffuse object with a speckle interferometer is presented. Methods for evaluating a speckle interferogram using digital image processing techniques are also discussed. The system consists of an interferometric optical setup and a computer-TV image processing facility. A speckle interferogram
S, Nakadate, T, Yatagai, H, Saito
openaire +2 more sources
Differential Speckle Interferometry
Optica Acta: International Journal of Optics, 1982This paper describes an experiment in narrow spectral band speckle interferometry, which uses variations in the spectrum across the astronomical object under study, to obtain information of the object on the millisecond of arc scale. We plan to apply this experiment to the study of spectroscopic double stars, stellar rotation, spectroscopic and ...
openaire +1 more source
High speed speckle interferometry
SPIE Proceedings, 2006The basic optical set-ups used for speckle interferometry have a limited capability to study transient events due to the synchronization with the acquisition devices. This capability is explored in this work and compared with recent developed techniques such as the temporal phase unwrapping.
A. Davila, V. Pinto, G. Garnica
openaire +1 more source
Astronomical Speckle Interferometry
Joint Topical Meeting on Information Processing in Astronomy and Optics, 1983Antoine Labeyrie first pointed out in 1970 that short exposure pictures of astronomical objects can be analyzed in a simple way to recover information about the objects' structures down to the diffraction limit of a telescope. Labeyrie's method, which rather quickly came to be called speckle interferometry, takes advantage of the convolution theorem to
openaire +1 more source
Measuring Microvibrations by Heterodyne Speckle Interferometry
Optics Letters, 1981In-plane as well as out-of-plane displacements and vibrations of objects with diffusely scattering surfaces are measured in real time. Microvibrations with amplitudes down to 1 nm and frequencies up to 5 MHz were analyzed at a spatial resolution of 35microm.
R, Dändliker, J F, Willemin
openaire +2 more sources
1978
Publisher Summary This chapter discusses the nature of the speckle pattern and defines some of its basic characteristics. The speckle effect in optics is the generation of a random intensity pattern formed when coherent light is scattered by a rough surface or is diffused by a medium containing scattering centers.
openaire +1 more source
Publisher Summary This chapter discusses the nature of the speckle pattern and defines some of its basic characteristics. The speckle effect in optics is the generation of a random intensity pattern formed when coherent light is scattered by a rough surface or is diffused by a medium containing scattering centers.
openaire +1 more source