Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Confocal signal evaluation algorithms for surface metrology: uncertainty and numerical efficiency

Not Accessible

Your library or personal account may give you access

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.

© 2017 Optical Society of America

Full Article  |  PDF Article
More Like This
Influence of sample surface height for evaluation of peak extraction algorithms in confocal microscopy

Cheng Chen, Jian Wang, Xiaojun Liu, Wenlong Lu, Hong Zhu, and Xiangqian (Jane) Jiang
Appl. Opt. 57(22) 6516-6526 (2018)

Systematic errors on curved microstructures caused by aberrations in confocal surface metrology

Maik Rahlves, Bernhard Roth, and Eduard Reithmeier
Opt. Express 23(8) 9640-9648 (2015)

Signal evaluation for high-speed confocal measurements

A. K. Ruprecht, T. F. Wiesendanger, and H. J. Tiziani
Appl. Opt. 41(35) 7410-7415 (2002)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (6)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (28)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved