Details
| Original language | English |
|---|---|
| Pages (from-to) | 5920-5926 |
| Number of pages | 7 |
| Journal | Applied Optics |
| Volume | 56 |
| Issue number | 21 |
| Publication status | Published - 17 Jul 2017 |
Abstract
Confocal microscopy is one of the dominating measurement techniques in surface metrology, with an enhanced lateral resolution compared to alternative optical methods. However, the axial resolution in confocal microscopy is strongly dependent on the accuracy of signal evaluation algorithms, which are limited by random noise. Here, we discuss the influence of various noise sources on confocal intensity signal evaluating algorithms, including center-of-mass, parabolic least-square fit, and cross-correlation-based methods. We derive results in closed form for the uncertainty in height evaluation on surface microstructures, also accounting for the number of axially measured intensity values and a threshold that is commonly applied before signal evaluation. The validity of our results is verified by numerical Monte Carlo simulations. In addition, we implemented all three algorithms and analyzed their numerical efficiency. Our results can serve as guidance for a suitable choice of measurement parameters in confocal surface topography measurement, and thus lead to a shorter measurement time in practical applications.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Atomic and Molecular Physics, and Optics
- Engineering(all)
- Engineering (miscellaneous)
- Engineering(all)
- Electrical and Electronic Engineering
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In: Applied Optics, Vol. 56, No. 21, 17.07.2017, p. 5920-5926.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Confocal signal evaluation algorithms for surface metrology
T2 - uncertainty and numerical efficiency
AU - Rahlves, Maik
AU - Roth, Bernhard
AU - Reithmeier, Eduard
PY - 2017/7/17
Y1 - 2017/7/17
N2 - Confocal microscopy is one of the dominating measurement techniques in surface metrology, with an enhanced lateral resolution compared to alternative optical methods. However, the axial resolution in confocal microscopy is strongly dependent on the accuracy of signal evaluation algorithms, which are limited by random noise. Here, we discuss the influence of various noise sources on confocal intensity signal evaluating algorithms, including center-of-mass, parabolic least-square fit, and cross-correlation-based methods. We derive results in closed form for the uncertainty in height evaluation on surface microstructures, also accounting for the number of axially measured intensity values and a threshold that is commonly applied before signal evaluation. The validity of our results is verified by numerical Monte Carlo simulations. In addition, we implemented all three algorithms and analyzed their numerical efficiency. Our results can serve as guidance for a suitable choice of measurement parameters in confocal surface topography measurement, and thus lead to a shorter measurement time in practical applications.
AB - Confocal microscopy is one of the dominating measurement techniques in surface metrology, with an enhanced lateral resolution compared to alternative optical methods. However, the axial resolution in confocal microscopy is strongly dependent on the accuracy of signal evaluation algorithms, which are limited by random noise. Here, we discuss the influence of various noise sources on confocal intensity signal evaluating algorithms, including center-of-mass, parabolic least-square fit, and cross-correlation-based methods. We derive results in closed form for the uncertainty in height evaluation on surface microstructures, also accounting for the number of axially measured intensity values and a threshold that is commonly applied before signal evaluation. The validity of our results is verified by numerical Monte Carlo simulations. In addition, we implemented all three algorithms and analyzed their numerical efficiency. Our results can serve as guidance for a suitable choice of measurement parameters in confocal surface topography measurement, and thus lead to a shorter measurement time in practical applications.
UR - http://www.scopus.com/inward/record.url?scp=85025708886&partnerID=8YFLogxK
U2 - 10.1364/AO.56.005920
DO - 10.1364/AO.56.005920
M3 - Article
C2 - 29047912
AN - SCOPUS:85025708886
VL - 56
SP - 5920
EP - 5926
JO - Applied Optics
JF - Applied Optics
SN - 1559-128X
IS - 21
ER -