Holographic interferometry
Holographic interferometry (HI) is a technique that enables the measurement of static and dynamic displacements of objects with optically rough surfaces at optical interferometric precision (i.e., to fractions of a wavelength of light). These measurements can be applied to stress, strain, and vibration analysis, as well as to non-destructive testing and radiation dosimetry.
Source: Wikipedia — Holographic interferometry (CC BY-SA 4.0)