DHSPIaims to investigate and monitor deformation, deterioration, and fracture mechanisms and thus to evaluate the structural condition of materials and systems as a result of ageing, mechanical alteration and materials’ failure. Holographic interferometry is a very well‐established optical technique for research in cultural heritage, which brings together some very basic and critical properties such as contactless examination and non-destructivity, accuracy, repeatability, and a wide range of applicability.

This diagnostic technique is based on the physical phenomenon of interference, that is, the superposition of two electromagnetic waves, and its application in holography and holographic interferometry. In holography, the laser beam is split into two parts, the object beam and the other serving as the reference beam. The object beam is used to illuminate the object of interest and strikes then the recording medium, after being reflected or scattered by the object. The reference beam is heading directly on the recording medium, where it interacts with the light coming from the object to create an interference pattern. In digital holography, the recording of holograms is performed with the help of a digital sensor array (charge‐coupled device [CCD] camera) and appropriate reconstruction algorithms, with the help of which the reference and diffracted wavefronts are simulated