22 December 2014 Spatio-temporal phase retrieval in speckle interferometry with Hilbert transform and two-dimensional phase unwrapping
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Abstract
Hilbert transform (HT) is widely used in temporal speckle pattern interferometry, but errors from low modulations might propagate and corrupt the calculated phase. A spatio-temporal method for phase retrieval using temporal HT and spatial phase unwrapping is presented. In time domain, the wrapped phase difference between the initial and current states is directly determined by using HT. To avoid the influence of the low modulation intensity, the phase information between the two states is ignored. As a result, the phase unwrapping is shifted from time domain to space domain. A phase unwrapping algorithm based on discrete cosine transform is adopted by taking advantage of the information in adjacent pixels. An experiment is carried out with a Michelson-type interferometer to study the out-of-plane deformation field. High quality whole-field phase distribution maps with different fringe densities are obtained. Under the experimental conditions, the maximum number of fringes resolvable in a 416×416 frame is 30, which indicates a 15λ deformation along the direction of loading.
© 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)
Xiangyu Li, Xiangyu Li, Zhanhua Huang, Zhanhua Huang, Meng Zhu, Meng Zhu, Jin He, Jin He, Hao Zhang, Hao Zhang, } "Spatio-temporal phase retrieval in speckle interferometry with Hilbert transform and two-dimensional phase unwrapping," Optical Engineering 53(12), 124104 (22 December 2014). https://doi.org/10.1117/1.OE.53.12.124104 . Submission:
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