Modified in-line speckle interferometric configuration for contouring of three-dimensional objects

A modified in-line optical configuration in speckle interferometry is presented here for contouring in three-dimensional objects. This configuration uses single beam illumination and two directions of observation as in Duffy's configuration but the sensitivity obtainable is equal to that of Leendertz's configuration. This configuration is simple to implement and provides the possibility to vary the sensitivity over a wide range. The detailed theory and experimental results are presented.