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An Improved Synthesis Phase Unwrapping Method Based on Three-Frequency Heterodyne.
Jiangtao Liu1, Peng Tian2, Hongru Li1
1College of Electronics and Information Engineering, Sichuan University, Chengdu 610065, China.
Sensors (Basel, Switzerland)
|December 11, 2022
Summary
This study introduces an improved three-frequency heterodyne synthesis phase unwrapping method. The technique enhances measurement accuracy by reducing noise and increasing equivalent phase frequency, validated through simulations and experiments.
Area of Science:
- Optics and Photonics
- Metrology
- Signal Processing
Background:
- Phase unwrapping is crucial for accurate measurements in interferometry and optical metrology.
- Traditional methods struggle with noise and limited frequency ranges, impacting measurement precision.
- Heterodyne interferometry offers potential for high-accuracy measurements but requires robust phase unwrapping.
Purpose of the Study:
- To propose an improved three-frequency heterodyne synthesis phase unwrapping method.
- To enhance measurement accuracy by mitigating noise and increasing equivalent phase frequency.
- To introduce a robust phase thresholding technique using Otsu segmentation.
Main Methods:
- Utilized phase difference and phase sum operations for improved phase unwrapping.
- Implemented Otsu segmentation to determine phase thresholds based on phase difference distribution.
- Investigated appropriate period combinations for optimal performance.
- Employed simulations and experimental validation.
Main Results:
- The proposed method effectively reduces the impact of noise on phase measurements.
- Achieved an increased equivalent phase frequency compared to existing methods.
- Otsu segmentation provided a reliable method for phase threshold determination.
- Demonstrated improved measurement accuracy through simulations and experiments.
Conclusions:
- The developed three-frequency heterodyne synthesis phase unwrapping method significantly enhances measurement accuracy.
- The integration of Otsu segmentation and phase sum operations provides a robust solution for phase unwrapping challenges.
- The method shows strong potential for applications requiring high-precision optical measurements.
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