11 September 2001 Robust spatial phase-stepping ESPI system
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Proceedings Volume 4420, Laser Metrology for Precision Measurement and Inspection in Industry; (2001) https://doi.org/10.1117/12.439205
Event: Laser Metrology for Precision Management and Inspection in Industry, 2001, Florianopolis, Brazil
A new algorithm is described that uses only two mutually phase-shifted interferograms per deformation state and a mean intensity in order to retrieve the phase signal modulo 2 (pi) due to displacement. The algorithm was designed for spatial phase-stepping ESPI where the initial phase in the interference term is the phase of speckle that varies randomly over the imagine sensor. An analysis of phase measurement error is presented. System error sources considered here are imperfect phase stepping, variation of modulation depth and intensity noise. The algorithm was implemented into an out-of-plane sensitive interferometer for experimental verification. The paper discusses practical advantages, presents limitations and possible future enhancements of the system. Obtained experimental results prove that phase measurement uncertainties smaller than 2 (pi) /15 are feasible.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Meinhard Sesselmann, Armando Albertazzi, "Robust spatial phase-stepping ESPI system", Proc. SPIE 4420, Laser Metrology for Precision Measurement and Inspection in Industry, (11 September 2001); doi: 10.1117/12.439205; https://doi.org/10.1117/12.439205

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