Many modern technologies for the production of nanomaterials require an operational diagnostic with a high defect detection capability for the products immediately during the production process. These technologies include, in particular, plasma nanotechnologies for the creation of nanostructures and coatings, electron-beam epitaxy technologies, new deposition technologies for films and coatings, bulk and surface nanostructuring of metallic materials, technologies for making multilayer dislocation-free silicon nanostructures for electronic devices; technologies for fabricating optical mirrors based on nanostructured powders of silicon and its chemical compounds; roll technologies for fabrication of diffraction elements and solar cell matrices, nanostructured substrates for nano- and microelectronics. The distinctive features of these technologies are their high productivity, the different sizes of the work pieces, strict specifications on the topological characteristics of surface shapes and textures, and the thicknesses and optical characteristics of films and coatings. During execution of most of these technologies, primary attention is devoted to the search for and analysis of defects whose dimensions are much smaller than an optical wavelength. These measurements are needed both in final production and in engineering setup, i.e., the nanostructured substrates on which the work pieces are formed, the master matrices used in rolling technologies, etc. An analysis of technologies of this kind makes it possible to formulate specifications for the measurement and diagnostic equipment used in these technologies: contactless measurements, high productivity, in situ measurements, the ability to detect defects of nanometer size. Optical methods are generally used for this kind of measurements in production lines, e.g., interferometry, including holographic and speckle interferometry, ellipsometry, confocal and scanning microscopy, all with a high operational measurement capacity and noninvasive. Improvements in these methods have led to some surprising results. Modern optical systems make it possible to measure deviations in the shape and structure of surfaces with an error of 0.1‐0.2 nm, determine a lateral change in an object by 3‐5 nm, and measure the thicknesses of multilayer coatings with an accuracy of 1‐2 nm [1, 2]. These systems must be capable of measuring 5‐10 wafers per hour for diagnostics of 1‐2 gigapixel work pieces. All the above remarks are confirmed by the need to develop apparatus and methods in the nanoindustry with modern instrumentation for contactless operational monitoring of surface nanorelief and texture in the manufactured products. The use of optical measurement techniques presupposes, first of all, the establishment of a relationship between the parameters of the detected light and the properties of a material, second, the use of optical devices for measuring the parameters of the light, and, third, recovery of the properties of the material from the measured parameters of the light.