Results 161 to 170 of about 20,656 (214)

Spiral interferogram analysis

Journal of the Optical Society of America A, 2006
Interference microscopy using spatial Fourier filtering with a vortex phase element leads to interference fringes that are spirals rather than closed rings. Depressions and elevations in the optical thickness of the sample can be distinguished immediately by the sense of rotation of the spirals. This property allows an unambiguous reconstruction of the
Alexander, Jesacher, Severin, Fürhapter, Stefan, Bernet, Monika, Ritsch-Marte   +3 more
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Single frame interferogram evaluation

Applied Optics, 2008
We present a simple and novel algorithm for the phase extraction from a single interferogram based on the spatial processing of interference patterns. This new evaluation procedure is suitable for application in environments where the presence of vibrations impedes the use of a classical phase-shifting interferometry scheme with multiple exposures. The
Eugenio, Garbusi, Christof, Pruss, Wolfgang, Osten   +2 more
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Interferogram reduction for radial-shear and local-reference-holographic interferograms

Applied Optics, 1986
In local reference holographic interferometry and radial shear interferometry, a small portion of the test beam is magnified and used as the reference for the rest of the wave front. The reference portion may be off-center or contain aberrations that complicate measurement of the wave front.
D R, Kohler, V L, Gamiz
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Unwrapping circular interferograms

Applied Optics, 2000
The Green's formulation for phase unwrapping is generalized to the case of circular phase-support regions. A phase-unwrapping method, believed to be new, is developed in which two forms of the Green's function are used, one in a closed form and the other in the form of a series of Helmholtz equation eigenfunctions to satisfy homogeneous Neumann ...
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Step Heights from Interferograms

Applied Optics, 1973
For the precise determination of a step height, the surface contour in the vicinity of the step must be determined. Methods that have proven satisfactory even in the presence of aberrations caused by poor flatness of object or comparison mirrors, by auxiliary optics, or by subsequent processing are described.
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Computer aided evaluation of interferograms

Experiments in Fluids, 1993
A semi-automatic technique is presented for obtaining the density field from interferograms provided by a Mach-Zehnder setup in infinite fringe width adjustment using short exposure times. The algorithm relies on extracting the fringe edges from the original image and then numbering the resulting polygons according to their order of interference using ...
Bartels-Lehnhoff, H.H., Baumann, P.H., Bretthauer, B., Meier, G.E.A.   +3 more
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Digital evaluation of interferograms

Measurement, 2004
Abstract For one and a half decade, software for interferometric fringe evaluation has been developed and used at Graz University of Technology. Within the framework of an awarded grant, these software packages on interferometric fringe evaluation were subsumed under Windows and Unix platforms and are accessibly under http://optics.tugraz.at .
M. Hipp, J. Woisetschläger, P. Reiterer, T. Neger   +3 more
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Virtual interferogram-generation algorithm for phase measurement using two interferograms

SPIE Proceedings, 2016
Phase-shifting digital holography is a technique for phase measurement with high spatial resolution and applied to many fields. This technique typically requires four phase-shifted interferograms between a signal beam and a reference beam. We focused on the two-step phase shifting algorithm, which needs only two phase-shifted interferograms and an ...
Jin Nozawa, Atsushi Okamoto, Masataka Toda, Yasuyuki Kuno, Akihisa Tomita   +4 more
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An Automated Interferogram Analysis Technique

Applied Optics, 1968
An automated technique has been developed for the analysis of various types of interferograms. The technique makes use of a high speed digitized microdensitometer to scan the interferograms and a high speed computer to perform the required computations.
R A, Jones, P L, Kadakia
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Multitemporal SAR interferograms simulator

2006 2nd International Conference on Information & Communication Technologies, 2006
Many are the examples of SAR and differential SAR interferometry application as well for ground elevation measurements as for surface deformation monitoring. A large number of interferometric techniques use instead of a single interferogram a database of multitemporal interferograms covering the same region.
C. Ferdaous, T. Florence, M. Henri
openaire   +1 more source