High-sensitive interferometric control of the quality of diffractive elements

The prospects of the long lateral shear interferometry for controlling the quality of diffractive elements are shown. In this case, use is made of two diffractive elements, one of which is under investigation, and the other is the model one. A universal device is proposed to control the quality of the diffractive elements of both transmission and reflection types. We present the results of experimental realisation of the technique for the quality control of production of two-dimensional amplitude masks and reflection diffraction gratings.