Visualisation of the wave-front deformations caused by a phase object by the method of successive double lateral shear interferometry

The method of moire visualisation of the wave-front deformations of a light beam propagated through a phase object is proposed. The method is based on the recording of double shear interferograms and makes it possible to obtain real-time moire pictures of the phase object with doubled sensitivity, in which the behaviour of fringes is similar to that in usual double-beam, reference-wave interferometry. The method was tested by studying the regions of thermal treatment of a polymethyl methacrylate plate.