Digital speckle pattern interferometry (DSPI) and digital shearography (DS) are well known optical tools for qualitative as well as quantitative measurements of displacement components and its derivatives of engineering structures subjected either static or dynamic load. Spatial phase shifting (SPS) technique is useful for extracting quantitative displacement data from the system with only two frames. Optical configurations for DSPI and DS with a double aperture mask in front of the imaging lens for spatial phase shifting are proposed in this paper for the measurement of out-of-plane displacement and its first order derivative (slope) respectively. An error compensating four-phase step algorithm is used for quantitative fringe analysis.

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Characterization of deformation and surface shape is an important parameter in quality testing of micro-objects in view of the functionality, reliability, and integrity of the components. Single-wavelength TV holography is widely used for deformation analysis. However, the single-wavelength TV holographic configuration suffers from overcrowding of fringes for large deformation that sets a limitation due to speckle decorrelation for quantitative fringe analysis. Furthermore, shape cannot be determined when using single wavelength. In this paper, we describe a multiple-wavelength microscopic TV holographic configuration that uses sequentially recorded phase-shifted frames at three different wavelengths before and after deformation of the specimen for evaluation of relatively large deformation fields at the effective wavelengths. Use of multiple wavelengths for deformation and shape evaluation is discussed. The design of the system along with the experimental results on smallscale rough specimens under static load is presented.