A simple method of fringe control in holographic non-destructive testing

The fringe control techniques are of immense importance for removing high spatial frequency fringe patterns arising as a result of the overall motion or gross structural deformation of the object when it is subjected to a stress field. The removal of these high spatial frequency fringe patterns is necessary to observe the region of defect in the object vividly. A simple method of fringe control for these unwanted fringes is described.