Coherent optical system with a synthesized aperture for determination of geometric parameters of an object

A study is reported of optical systems with a resolving power better than the diffraction limit. Such systems are based on optical synthesis of an aperture involving introduction of a replicating optical component (for example, a diffraction grating) into the object space. A light beam corresponding to a spatial frequency (of the object spectrum) lying outside the limits of the aperture is deflected by such a component so that it falls within the aperture. An analysis is made of the use of ultra-high-resolution systems of this kind in industry for the determination of linear dimensions and displacements. It is shown that the local surface microrelief can be deduced from the degree and nature of the distortion of the image of a point object.