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Implementation of a Reference Interferometer for Nanodetection
Published on: April 26, 2014
Distance measurement technique using tilted interference fringe systems and receiving optic matching.
Philipp Günther1, Robert Kuschmierz, Thorsten Pfister
1TU Dresden, Laboratory for measurement and testing techniques, Dresden 01062, Germany. philipp.guenther@tu‑dresden.de
Optics Letters
|November 21, 2012
Summary
This study introduces a novel method to improve distance measurements for fast-moving rough surfaces using a non-incremental interferometer. The technique significantly enhances signal correlation, reducing measurement uncertainty for applications like lathe monitoring.
Area of Science:
- Optical Metrology
- Surface Characterization
- Interferometry
Background:
- Precise distance measurement of moving rough surfaces is crucial for applications like lathe monitoring.
- Non-incremental interferometers with tilted fringe systems are used but face challenges due to speckle effects.
- Speckle causes phase jumps and random envelopes, leading to low correlation and high uncertainty in distance measurements.
Purpose of the Study:
- To present a novel method for enhancing signal correlation in non-incremental interferometry for rough surfaces.
- To significantly improve the accuracy of distance measurements for fast-moving surfaces.
- To enable precise determination of the shape of rotating objects by combining distance and velocity measurements.
Main Methods:
- Utilizing a non-incremental interferometer with two tilted interference fringe systems.
- Generating interference signals from scattered light of a rough surface illuminated from two different directions.
- Implementing a matching of illumination and receiving optics to enhance signal correlation.
Main Results:
- Achieved distance measurements with uncertainty as low as 1.2 μm at lateral velocities of approximately 10 m/s.
- Significantly enhanced the signal correlation coefficient, overcoming speckle-induced limitations.
- Enabled simultaneous measurement of lateral velocity alongside distance.
Conclusions:
- The developed method effectively mitigates speckle effects in interferometric measurements.
- This technique offers a substantial improvement in the precision of distance and velocity measurements for dynamic surfaces.
- The precise shape determination of rotating objects is now feasible with this advanced interferometric approach.
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