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Journal ArticleDOI

Surface Profiling by Analysis of White-light Interferograms in the Spatial Frequency Domain

Peter J. de Groot, +1 more
- 01 Feb 1995 - 
- Vol. 42, Iss: 2, pp 389-401
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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.

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Citations
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Dissertation

Interferometrische Sensoren mit Modulation der optischen Weglänge für die Fertigungsmesstechnik

TL;DR: In this paper, the optical path length modulation (OPLM) in the reference arm of an interferometric measurement system is used for measurements of nm accuracy with a measurement range of up to 100μm.
Journal ArticleDOI

Vibration Compensated, Scanning White Light Interferometer for In Situ Depth Measurements in a Deep Reactive Ion Etcher

TL;DR: In this paper, a scanning white light interferometer with a long working distance and active vibration cancellation was designed and tested to enable in situ depth measurements in a deep reactive ion etcher.
Proceedings ArticleDOI

White light interferometry: innovative algorithms and performances

TL;DR: In this paper, two basic detection schemes are chosen as a function of the application requirements: superimposed on the photodetector and a single composite output signal, and the second scheme consists to separate optically the different wavelengths for a parallel detection and to measure the absolute value of the OPD without any mechanical displacement of the interferometer.
References
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Journal ArticleDOI

Optical coherence tomography

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

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.