Measurement of nanometric displacements by correlating two speckle interferograms

LUCAS P.TENDELA; G. E. GALIZZI; A. FEDERICO; G. H. KAUFMANN

APPLIED OPTICS

OPTICAL SOC AMER

Lugar: Washington; Año: 2011 vol. 50 p. 1758 - 1764

0003-6935

This paper presents a novel method to measure displacement fields in the nanometer range by using digital speckle pattern interferometry, which can be applied when the 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 proposed method to process real data is illustrated.