Journal ArticleDOI
Surface Profiling by Analysis of White-light Interferograms in the Spatial Frequency Domain
Peter J. de Groot,Leslie L. Deck +1 more
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TLDR
In this article, a scanning white-light interferometer for high-precision surface structure analysis is described, where the interferogram for each of the image points in the field of view is generated simultaneously by scanning the object in a direction perpendicular to the object surface, while recording detector data in digital memory.Abstract:
We describe a scanning white-light interferometer for high-precision surface structure analysis. Interferograms for each of the image points in the field of view of the instrument are generated simultaneously by scanning the object in a direction perpendicular to the object surface, while recording detector data in digital memory. These interferograms are then transformed into the spatial frequency domain and the surface height for each point is obtained by examination of the complex phase as a function of frequency. The final step is the creation of a complete three-dimensional image constructed from the height data and corresponding image plane coordinates. The measurement repeatability is better than 0·5 nm r.m.s. for a surface height range of 100 μm.read more
Citations
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Journal ArticleDOI
Wavelet transform as a processing tool in white-light interferometry
TL;DR: Results of the application of wavelet transform for signal processing in white-light interferometry are reported and the fringe envelope is addressed and permits a complete analysis of coherence-limited fringe patterns.
Journal ArticleDOI
Wavelength scanning profilometry for real-time surface shape measurement
TL;DR: Experiments where a tunable dye laser was used to simulate the real-time measurements of step objects with specular and diffuse surfaces have shown that a height map is available at any moment during the wavelength scan, and the measurement accuracy of height increases as the scanning proceeds.
Journal ArticleDOI
Simultaneous measurement of the phase and group indices and the thickness of transparent plates by low-coherence interferometry
Masamitsu Haruna,Masato Ohmi,Teruki Mitsuyama,Hideyuki Tajiri,Hideki Maruyama,Masahiro Hashimoto +5 more
TL;DR: A novel technique for simultaneous measurement of the phase index , the group index, n(g) , and the thickness, t, of transparent plates by use of a low-coherence interferometer is proposed and demonstrated.
Journal ArticleDOI
The enhancement of the properties of WC-Co HVOF coatings through the use of nanostructured and microstructured feedstock powders
TL;DR: In this article, three coatings have been obtained using nanostructured, bimodal and conventional WC-Co cermet powders by means of High Velocity Oxygen-Fuel (HVOF) technique.
Patent
Interferometric measuring device
Stefan Franz,Matthias Fleischer +1 more
TL;DR: In this article, an apparatus for an interferometric measuring device consisting of a first and a second interferometer was proposed, where the optical path lengths of the two partial beams are different to compensate for optical path difference between the two interferometers.
References
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Journal ArticleDOI
Optical coherence tomography
David Huang,Eric A. Swanson,Charles P. Lin,Joel S. Schuman,William G. Stinson,Warren Chang,Michael R. Hee,Thomas J. Flotte,Kenton W. Gregory,Carmen A. Puliafito,James G. Fujimoto +10 more
TL;DR: OCT as discussed by the authors uses low-coherence interferometry to produce a two-dimensional image of optical scattering from internal tissue microstructures in a way analogous to ultrasonic pulse-echo imaging.
Book ChapterDOI
Optical Coherence Tomography
Eric A. Swanson,J. Izatt,M. Bee,David Huang,Charles P. Lin,Carmen A. Puliafito,Carmen A. Puliafito,James G. Fujimoto +7 more
TL;DR: Optical coherence tomography (OCT) has developed rapidly since its first realisation in medicine and is currently an emerging technology in the diagnosis of skin disease as mentioned in this paper, where OCT is an interferometric technique that detects reflected and backscattered light from tissue.
Journal ArticleDOI
Digital phase-shifting interferometry: a simple error-compensating phase calculation algorithm.
TL;DR: La difference de phase entre les 2 faisceaux interferant varie de maniere connue et on fait des mesures de the distribution d'intensite a travers la pupille correspondant a au moins 3 dephasages differents.
Journal ArticleDOI
Optical coherence-domain reflectometry: a new optical evaluation technique.
TL;DR: An optical evaluation technique is described that is suitable for determining the positions and magnitudes of reflection sites within miniature optical assemblies using the coherence effects exhibited by a broadband optical source and is referred to as optical coherence-domain reflectometry.
Journal ArticleDOI
Three-dimensional sensing of rough surfaces by coherence radar
TL;DR: A three-dimensional sensor designed primarily for rough objects that supplies an accuracy that is limited only by the roughness of the object surface, which differs from conventional optical systems in which the depth accuracy is limited by the aperture.