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Published on: February 12, 2014
Suppression of aliasing in multi-sensor scanning absolute profile measurement
Axel Wiegmann1, Michael Schulz, Clemens Elster
1Physikalisch-Technische Bundesanstalt, Braunschweig, Germany. axel.wiegmann@ptb.de
Optics Express
|June 25, 2009
Summary
Reducing aliasing in multi-sensor scanning profile measurements is achievable. Careful selection of scanning steps significantly minimizes aliasing errors, enhancing measurement accuracy for fine details.
Area of Science:
- Metrology
- Optical Engineering
- Surface Metrology
Background:
- Absolute profile measurement using multi-sensor scanning techniques faces challenges with aliasing.
- Aliasing, an artifact in signal processing, distorts measurements when sampling is too coarse relative to the signal's frequency content.
Purpose of the Study:
- To investigate methods for reducing aliasing in absolute profile measurements.
- To demonstrate the effectiveness of optimized scanning steps in mitigating aliasing artifacts.
Main Methods:
- Simulations were performed to analyze the impact of scanning steps on aliasing.
- Interferometric measurements were conducted on a chirp specimen with varying sinusoidal wavelengths.
Main Results:
- Simulation results indicated that appropriate scanning steps can substantially reduce aliasing.
- Experimental validation using interferometry confirmed these findings, showing successful measurement of wavelengths down to 19 microm.
Conclusions:
- Optimizing scanning steps is a crucial strategy for effective anti-aliasing in multi-sensor scanning profile measurements.
- This approach enhances the precision and reliability of measuring fine surface features.
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