Measurement of nanometric displacements by correlating two speckle interferograms

TENDELA, LUCAS; GALIZZI, GUSTAVO; ALEJANDRO, FEDERICO; KAUFMANN, GUILLERMO

APPLIED OPTICS

OPTICAL SOC AMER

Año: 2011 vol. 50 p. 1758 - 1764

0003-6935

This paper presents a method to measure nanometric displacement fields using digital speckle pattern interferometry, which can be applied when the generated correlation fringes show less than one complete fringe. The method is based on the evaluation of the correlation between the two speckle interferograms generated by both deformation states of the object. The performance of the proposed method is analyzed using computer-simulated speckle interferograms. A comparison with the performance given by a phase-shifting technique is also presented, and the advantages and limitations of the proposed method are discussed. Finally, the performance of the proposedmethod to process real data is illustrated.