The article is devoted to the analysis and further improvement of the well-known Transfocal Scanning Optical Microscopy (TSOM) method, previously proposed by other authors. We analyze this approach step by step and simulate it thoroughly. Our simulation includes a rigorous numerical solution of the Maxwell equations for the electromagnetic field of light in an optical microscope using the Finite Difference in Time Domain (FDTD) method and the synthesis of a TSOM image in strict accordance with the original author’s instructions. After that, we propose an approach to the synthetic formation of three-dimensional phase images of nanometer scale objects with wave field back projection. We also carefully simulate is step by step, similarly to the previous one. Then we compare both the method newly proposed by us and the old one, using several benchmark test objects. We demonstrate the advantages of synthetic phase images over amplitude image synthesis. Finally, we show how the synthetic phase images can be used in pattern recognition algorithms for applied defectoscopic purposes.

Test objects of various types are utilized in the creation and utilization of video measuring systems that are part of robots' technical vision, television sight units, triangulation measuring systems, as well as 3D scanners. Simultaneously, a specific test object was created for each type of device. This paper examines the possibility of creating and constructing universal test objects for calibration (verification) of 2D and 3D video measuring systems that are used to measure the geometric parameters of two-dimensional (2D) and three-dimensional (3D) objects, respectively. We suggest using a liquid crystal monitor-based test object (measure) to calibrate 2D systems. This measure is calibrated using a high-precision laser interferometer displacement measurement device and subpixel image resolution algorithms. The developed measure corresponds to the standard of the 3rd category according to the State verification scheme for measuring instruments of length in the range of 1∙10−9–100 m and wavelengths in the range of 0.2–50 μm. This measure can be used to determine the modulation transfer function of a video system and the point spread function. To calibrate (verify) 3D systems, a gage block stack that can move in space according to a given program using a translator and an external linear encoder is proposed. We present the technical specifications of the developed measures that can be used as working standards for the calibration (verification) of a wide variety of video measuring systems.

The presented modification of the method of local optical tomography makes it possible to study the dynamic processes of subcellular structures of native nerve cells. The advantage of this approach is that it is possible to analyze the dynamics of the distribution of neuron structures at a point or area of interest inside the cell without performing a complete reconstruction of the cell image. It has been proved that it becomes possible to determine the dimensions, the cell area of interest, and the coordinates of subcellular structures for further study of their dynamics. In this modification, the method of local tomography could be used to study both cells and cellular structures, because it is not necessary to probe a full field of view. Local probing of the region of interest during the functioning of the nerve cell will, first, reduce the time of data recording for obtaining local tomograms and second, provide the opportunity to explore the dynamics of several regions inside the cell at the same time.

The paper presents a new original technique for accurate reconstructing the wave front phase at interferometry measurements based upon the estimation of the signals’ amplitudes. The optical signals’ processing is implemented within the Rice statistical model. The required phase of the wave front to be reconstructed is calculated from the geometrical considerations from the calculated undistorted amplitudes values. The paper provides both the mathematical basics of the technique and the results of its testing by means of both numerical and physical experiments. The proposed technique can be efficiently applied in a wide circle of scientific and technical tasks in numerous ranging and communication systems.

An automated interference microscope has been used to determine the rms amplitude of fluctuations of living cells in vitro. The geometric thickness of cells has been calculated based on the measured optical path differences of light waves and the equivalent elastic constants of these cells have been estimated. The determined rms amplitude of fluctuations of the optical path difference is 0.3–2.7 nm, which corresponds to 4–40 nm rms amplitude of membrane-thickness fluctuations. The amplitudes of fluctuations of spread cells (endothelial cells and macrophages) are smaller relative to unattached cells (in vitro red blood cells and lymphocytes). At the same time, the amplitude of fluctuations observed in HeLa tumor cells spread on a substrate exceeds the amplitude of fluctuations of other spread cells (endothelial cells and macrophages). The obtained experimental data are in agreement with the earlier results obtained using other optical methods.

An interference microscopy-based method for measuring the refractive index of microscopic objects is considered. It is shown that of special interest is the analysis of the dispersion of the refractive index of small objects of biological fluids, which can make it possible to separate fluctuations of the size and the refractive index of the object in studying living cells by methods of phase microscopy. A method for measuring the dispersion of the refractive index of microscopic volumes of fluids using the MIA-1D automated interference microscope and a measuring cell with a microwell is described. An algorithm for processing the obtained images with the aim of calculating the refractive index is presented. The measurement results for the dispersion of the refractive index of bovine serum albumin are given. It is shown that the proposed method allows one to measure the refractive index of fluids in microscopic volumes up to four or five decimal places.

Рассмотрен метод измерения показателя преломления микроскопических объектов, основанный на интерференционной микроскопии. Показано, что особый интерес представляет анализ дисперсии показателя преломления малых объемов биологических жидкостей, что может позволить при исследовании живых клеток методами фазовой микроскопии разделить флуктуации размера объекта и его показателя преломления. Описан метод измерения дисперсии показателя преломления микроскопических объемов жидкостей с помощью автоматизированного интерференционного микроскопа МИА-1Д и измерительной кюветы с микролункой. Приведено описание алгоритма обработки получаемых изображений с целью вычисления показателя преломления. Приведены результаты измерения дисперсии показателя преломления бычьего сывороточного альбумина. Показано, что предложенный метод позволяет измерять показатель преломления жидкостей микроскопических объемов с точностью до 4-5-го знака после запятой. Ключевые слова: рефрактометрия, показатель преломления, лазерная интерференционная микроскопия, альбумин.

The article focuses on the achievements of Soviet and Russian scientists in the development of diffraction optics and digital holography. The authors also analyze the current status of digital holography regarding both the traditional areas related to visualization in the visible range, and the development of new frequency ranges from x-rays to terahertz frequencies.

The composition, operating principle, and basic metrological characteristics of GET 186–2017, the State Primary Standard of units of ellipsometric angles, a Standard that supports measurement of the two-dimensional spatial distribution of ellipsometric angles, are described. The structure of GET 186–2017 includes a spectral ellipsometer equipped with a x, y-stage for measurements on a grid of 10 × 10 points and an interference profilometer by means of which a two-dimensional map of deviations from 90° of the normals to the surface of an object may be measured. Measurements are not performed at scanning points where the deviation of the normal exceeds 0.01°. Through measurement of the two-dimensional spatial distribution of ellipsometric angles it is possible to establish the spatial distribution of the thickness and complex indicator of refraction of the coatings across the area of a test article. GET 186–2017 supports the uniformity of measurements in highly important trends in science and technology, such as microelectronics, optics, and instrument construction. The principal users of GET 186–2017 are organizations involved in the development of new articles in microelectronics, solar batteries, and optics, in particular, laser gyroscopes. Ordered multilayer structures deposited on a substrate where the thickness of these structures is monitored by means of different types of ellipsometers, including image ellipsometers, are components of such structures.

A measurement system for the detection of a low concentration of nanoparticles based on optical microcavities with whispering-gallery modes (WGMs) is developed and investigated. A novel method based on the WGM broadening allows us to increase the precision of concentration measurements up to 0.005 ppm for nanoparticles of a known size. We describe WGM microcavity manufacturing and quality control methods. The collective interaction process of suspended Ag nanoparticles in a liquid and TiO2 in the air with a microcavity surface is studied.

The creation of measuring systems for additive processes is hindered by the lack of diagnostic and control systems for manufactured products.The quality of the parts obtained by the methods of additive technologies varies greatly due to inadequate dimensional tolerances, surface roughness, as well as defects and the presence of fields of mechanical stresses.This leads to the fact that the slightest deviation of external conditions arising in the manufacturing process, can cause a mismatch of the final product in shape or properties.The measuring system should have the potential to be integrated into a single production complex.This is due to the fact that the result of measuring the geometric parameters of specific products must be compared with the mathematical model developed in the CAD system, and measurements of defects, latent stresses, product structures must be transferred to the CAE system to decide on the suitability of the product or to develop an algorithm and technologies for its further processing.To control the parameters of products of additive technologies, a system based on the methods of structured light and shearography is proposed.

The article presents the various problems in the metrological support for the components of quantum information systems and uses the Klyshko reference method given in the international ETSI standard, which works on the principle of spontaneous parametric scattering effect. It is found that the measurement time has increased by an order of magnitude at noise level with a high power density at low frequencies when compared to desired signal level for single-photon detectors. So, the heterodyning method is proposed to increase the efficiency of signal accumulation. The method consists in accumulating a signal at a higher frequency and introducing modulation into the standard Klyshko scheme. The method proposed is simulated numerically and the signal-to-noise ratio is increased by a factor of 14 compared to simple signal accumulation has been established experimentally.

We have numerically simulated the process of measuring stress-strain states by the method of speckle-shearing interferometry using the phase-shift technique. A computer model with the possibility of setting its strain and roughness is developed, which includes a model of a diffusely reflecting test object corresponding to the characteristics of a real membrane, as well as a speckle interferometer model that allows speckle interferograms to be obtained for different speckle sizes and angles between interfering beams. The process of reconstructing the object surface topogram from model speckle interferograms by the phase-shift technique is implemented. Using the developed models, a two-dimensional shearogram are obtained, which is a derivative of the strain field of a circular membrane. Comparison of the results of numerical simulation with experimental data shows that the differences (rms deviations) do not exceed 0.02 mu m. It is also shown that the error of interferogram reconstruction by the phase-shift technique increases significantly when the test object strains exceed 12 mu m.

The creation of measuring systems for additive processes is hindered by the lack of diagnostic and control systems for manufactured products. The quality of the parts obtained by the methods of additive technologies varies greatly due to inadequate dimensional tolerances, surface roughness, as well as defects and the presence of fields of mechanical stresses. This leads to the fact that the slightest deviation of external conditions arising in the manufacturing process, can cause a mismatch of the final product in shape or properties. The measuring system should have the potential to be integrated into a single production complex. This is due to the fact that the result of measuring the geometric parameters of specific products must be compared with the mathematical model developed in the CAD system, and measurements of defects, latent stresses, product structures must be transferred to the CAE system to decide on the suitability of the product or to develop an algorithm and technologies for its further processing. To control the parameters of products of additive technologies, a system based on the methods of structured light and shearography is proposed.

A source of correlated photon pairs based on spontaneous parametric scattering is developed and created. The source may be used both as a probabilistic source of single-photon radiation with low value of the parameter g(2)(0) and as a bi-photon source for the quantum distribution of keys based on the Einstein–Podolskiy–Rosen paradox as well as for the Klyushko–Penin reference method of determining the quantum efficiency of detectors of low-photon radiation. Experimental results of the generation of bi-photons for pairs of wavelengths of 651 nm (signal wave) and 1100 nm (idler wave) are presented. The quantum efficiency of a low-photon 651-nm wavelength detector is measured by means of this source using the Klyushko–Penin reference method. The new source may be tuned comparatively easily over a broad range of wavelengths from 558 to 1550 nm.

A calibration device intended for metrological assurance of instruments used to measure deformations and displacements by methods of electronic speckle interferometry and shearography is developed. The optical methods presented here may be applied to different types of materials possessing rough surfaces. The proposed device reproduces stress-strain states by means of elastic deformation of the surface of a membrane through the use of a rod and leverage. Calibration of the device is performed, its transfer characteristics are investigated, and the nonlinearity of the displacement of the surface of the membrane is estimated. Results of experiments designed to measure the stress-strain state with the use of the noncontact method of shearography are presented. The phase image produced by deformation of the membrane is described and the metrological characteristics of the calibrated device are estimated. It is shown that through the use of the present calibration device it is possible to use optical methods not only for qualitative assessment of the deformation of objects of complex shape, but also for quantitative estimation of the geometric characteristics of these objects.

We consider a frequency-diaphragm technique of simultaneous standardless measurements of the efficiency of photon detection by two single-photon counters. This technique is based on the well-known scheme of measurements of the efficiency of detection of single photons with the help of photon pairs generated in a nonlinear crystal in the case of spontaneous parametric scattering. As a specific feature of the proposed procedure, we can mention the application of spectrally asymmetric optical channels. An experimental installation aimed at the realization of the proposed procedure in the degenerate mode of spontaneous parametric scattering is described. The results of simultaneous measurements of the detection efficiency of two single-photon counters at a wavelength of 810 nm are presented. The counters are constructed on the basis of SAP-500 silicon avalanche photodiodes with fiber inputs. It is shown that this technique can be also used for measuring the detection efficiency of single-photon counters sensitive in a more long-wave region of the spectrum. As compared with the pure diaphragm scheme, the proposed procedures has advantages in the simplicity and reliability of adjustment.

A microscope for studying internal inhomogeneities of the refractive index of optical dielectric microcavities by optical tomography is developed. The influence of these inhomogeneities on the Q factor of optical dielectric microcavities formed by thermal treatment is experimentally studied.