Speckle interferometry

The speckle interferometry is an imaging technic that uses laser light and can visualize and quantify the movement on the surface of an object between two states. It is used in laboratory and in field.

In making acquisitions at a regular rate (eg a few Hz), it is possible to monitor very finely object deformations over long periods (several days). The amplitudes measured total may reach several hundred microns.

Example: From a displacement field, we get quick deformations and mechanical stresses on the surface of a flat piece.