Conjugate wave holographic interferometry for the measurement of in-plane deformations.

A holographic interferometric technique is proposed whereby the interference fringes map one of the in-plane displacement components. The technique operates in real time by illuminating the undeformed object frontally and using two holograms to record two symmetrically scattered waves. On observation, the conjugates of the waves impinge on the object and reconstruct its real image. If the object is deformed, interference fringes can be seen on its surface. Some results obtained by a simplified setup are presented.