Simultaneous dual-wavelength phase-shifting interferometry for surface topography measurement
Abstract
To deal with vibration disturbance in interferometric measurement of surface topography, we present a simultaneous dual-wavelength phase-shifting interferometry (SDWPSI). SDWPSI collects phase-shifting interferograms of two wavelengths simultaneously with two cameras to accelerate data collection. The optical phases are retrieved from dual-wavelength interferograms with an iterative algorithm that is tolerant of phase-shifting error caused by vibration. And then the measured surface topography is reconstructed by fusing the phases of two wavelengths. Simulations and experiments verify that SDWPSI has a lower measurement noise than single-wavelength interferometry and extends the discontinuity limit to several micrometres. SDWPSI has advantages of high speed, vibration resistance, and low cost, and could be applied to in-workshop and on-machine measurement.
- Publication:
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Optics and Lasers in Engineering
- Pub Date:
- January 2020
- DOI:
- 10.1016/j.optlaseng.2019.105813
- Bibcode:
- 2020OptLE.12405813L
- Keywords:
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- Phase-shifting interferometry;
- Dual-wavelength interferometry;
- Iterative algorithm;
- Vibration resistance