Journal ArticleDOI
Three-dimensional imaging by sub-Nyquist sampling of white-light interferograms
Peter J. de Groot,Leslie L. Deck +1 more
TLDR
In this paper, the authors demonstrate a simple way of increasing the data acquisition and processing speed in a scanning white-light interferometer for surface topography measurement, which consists of undersampling interference data and processing the resultant sub-Nyquist interferograms in the frequency domain to create complete three-dimensional images.Abstract:
We demonstrate a simple way of increasing the data acquisition and processing speed in a scanning white-light interferometer for surface topography measurement. The method consists of undersampling interference data and processing the resultant sub-Nyquist interferograms in the frequency domain to create complete three-dimensional images. Experimental results on a 20-μm step height standard show a measurement repeatability of 10 nm.read more
Citations
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Journal ArticleDOI
Efficient nonlinear algorithm for envelope detection in white light interferometry
TL;DR: The new algorithm is shown to be near optimal in terms of computational efficiency and can be represented as a second-order nonlinear filter and in combination with a carefully designed peak detection method the algorithm exhibits exceptionally good performance on simulated interferograms.
Patent
Apparatus and method for ranging and noise reduction of low coherence interferometry LCI and optical coherence tomography OCT signals by parallel detection of spectral bands
TL;DR: In this paper, a method for increasing the sensitivity in the detection of optical coherence tomography and low coherence interferometry (LCI) signals by detecting a parallel set of spectral bands, each band being a unique combination of optical frequencies, is presented.
Journal ArticleDOI
High-speed noncontact profiler based on scanning white-light interferometry
Leslie L. Deck,Peter J. de Groot +1 more
TL;DR: A system for fast three-dimensional profilometry, of both optically smooth and optically rough surfaces, based on scanning white-light techniques, using an efficient algorithm to extract and save only the region of interference, substantially reducing both the acquisition and the analysis times.
Journal ArticleDOI
Surface Profiling by Analysis of White-light Interferograms in the Spatial Frequency Domain
Peter J. de Groot,Leslie L. Deck +1 more
TL;DR: 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.
Patent
Method and apparatus for performing optical imaging using frequency-domain interferometry
TL;DR: In this article, the first and/or second electro-magnetic radiations have a spectrum whose mean frequency changes substantially continuously over time at a tuning speed that is greater than 100 Tera Hertz per millisecond.
References
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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.
Journal ArticleDOI
Interferometric profiler for rough surfaces
TL;DR: A new method of optical, noncontact profiling of rough surfaces is described that utilizes interferometric techniques as well as digital signal-processing algorithms to produce fast, accurate, and repeatable three-dimensional surface profile measurements.
Journal ArticleDOI
Absolute optical ranging using low coherence interferometry
B. L. Danielson,C. Y. Boisrobert +1 more
TL;DR: In this article, a method for measuring submicrometer distances with an asymmetric fiber Michelson interferometer having an LED as a source of radiation is described, which is compatible with time domain sampling at the Nyquist rate.
Journal ArticleDOI
High-resolution OCDR for testing integrated-optical waveguides: dispersion-corrupted experimental data corrected by a numerical algorithm
TL;DR: In this article, a numerical algorithm is presented and applied to dispersion-corrupted experimental data taken by coherence domain reflectometric (OCDR) measurements, which results in a retrieval of micrometer resolution and an enhanced dynamic range.
Patent
Optical system for surface topography measurement
TL;DR: In this article, a white light interferogram is produced wherein the principal fringe indicates zero optical path difference between a test surface and a reference surface, and after each translation the position of the principal fringes is noted by observing the loci of points of maximum contrast.