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  • Installation for measuring longitudinal aberrations of mirror and lens lenses

    The operability of an optical device depends entirely on the quality of the optical parts that make up the optical system. Timely measurement of errors of optical parts in the process of surface shaping organizes feedback: the more accurately the error is measured, the more accurately the correction of the geometry of the surface is possible. Errors of optical surfaces and optical systems in general can be estimated by the mismatch of coordinates of real and ideal (calculated) profile curves of surfaces; mismatch of normals to this surface; difference of wave fronts in incident and refracted (or reflected) beams of light rays, etc.. The reproducibility of optical surfaces from sample to sample and their compliance with the calculated one is usually estimated by the discrepancy between the actual and theoretical functions of the course of light rays. Such a discrepancy is estimated by the aberrograms of optical systems, which are determined experimentally on special installations – aberrographs. Unlike the known schemes for measuring longitudinal aberrations of only reflectors or only lenses, the devel-oped installation is universal, designed to measure zonal aberrations of large-diameter mirror and lens lenses that are used in lighting devices, solar energy concentrators, transmitting and receiving optical systems of optoelectronic de-vices.

    Keywords: aberrometer, aberrogram, longitudinal aberration, lens lens, mirror lens

  • Remote determination of natural surface temperatures in the infrared (IR) region of the spectrum

    This article is devoted to the issues of remote sensing of natural surfaces in order to determine their temperatures by their own radiation in the infrared (IR) region of the spectrum. The basics of the radiometric method are briefly described, the factors influencing the result of remote measurements are analyzed. A formula is obtained by which the influence of ambient radiation (background) reflected from the studied surface on the result of thermodynamic temperature measurement is calculated. The calculation takes into account the emissivity of the reference black body, according to which the IR radiometer was calibrated, the background radiation temperature during calibration of the device and is performed for two spectral ranges located in the transparency window of the atmosphere. The calculation results are relevant for improving the accuracy of remote sensing of temperature fields of natural objects.

    Keywords: remote sensing, IR radiation, IR radiometer, temperature field, energy brightness, background radiation, blackbody, optical flux, radiation temperature, emissivity

  • Research of the geometric factors of the visual illusion that occurs when assessing the distances between the edges of objects

    The article is devoted to the study of the optical-geometric illusion that arises when estimating the distances between the edges of objects (in particular, circles). The subject of the study is the geometric factors that affect the magnitude of the illusion. The purpose of the study is aimed at obtaining quantitative estimates of the visual illusion and revealing the nature of the dependence of the magnitude of the illusion on its geometric parameters. The research method in this work was to conduct a computer experiment (testing) with subsequent statistical analysis of the data obtained as a result of the experiment. It has been established that the dependence of the magnitude of the distance illusion on the orientation factor has a periodicity of decrease-increase in the magnitude of the illusion when the test structure is rotated, while the maximum values ​​of the illusion are recorded at such a rotation of the test object, when the subject observes it in a vertical position. It is also confirmed that the illusion of distance is linearly dependent on the diameter of the circles: the larger the diameter of the circles, the brighter the illusion.

    Keywords: visual perception, visual illusions, optical-geometric illusions, Muller-Lyer illusion, distance illusion, geometric parameters of visual illusions

  • Physical foundations and results of the study of absorption in thin films of germanium doped with silicon

    Theoretical relations are presented that serve to estimate the absorbing properties of thin optical films using functions that determine the envelopes of interference extrema in the transmission spectrum of a thin optical film on a plane-parallel transparent substrate, as well as the experimental results of estimating infrared losses in Ge films doped with Si.

    Keywords: interference, absorption, optics, film, refractive index

  • Combined ophthalmopneumogoniometer

    The article presents the results of the development of the combined medical measuring device - an ophthalmopneumogoniometer, with the help of which it is possible to measure intraocular structures and pressure . Based on the results of the analysis of the subject area, the author proposed a structural diagram of the device, considered technical solutions of its individual elements.

    Keywords: ophthalmopneumogoniometer, ophthalmogoniometry, intraocular pressure, eye optics

  • Hybrid space power plants with laser light as elements of the energy system

    Hybrid space solar power stations with laser light emission, using inexhaustible energy of the Sun, provide environmentally clean energy, "green", as well as the development of space solar energy, which is a promising and relevant direction of energy system development in space (providing electric power to space equipment) and in the Earth energy system. Introduction of wireless energy transfer in the form of laser light makes it possible to focus the laser beam safely and with the least losses by semiconductor laser in the range of 0.55-0.75 µm or 1.0-1.1 µm windows of atmospheric transparency (Stage 1) followed by development of efficient fiber lasers with solar pumping at the same wavelength (Stage 2). The three variants of the solar energy transmission process from the Sun to the user in hybrid space solar power plants make it possible to provide electricity to underdeveloped and inaccessible regions without cable power transmission networks (areas in the Russian Far North, Central Siberia, Canada, Greenland, the Arctic and Antarctica, mountainous areas, deserts, natural disasters, disasters and continental shelf areas), as well as mobile, mobile transport and "smart grid" systems.

    Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility ofenvironmental energy, green energy, environmental safety, laser beam, space solar power plant

  • Accuracy investigation of color saturation contrast transform for digital images

    The audit to color saturation control tools of modern computer graphics software is carried out. Under assumption of the measuring application for saturation transform, the accompanying error is defined. In the case of a virtual instrument, this error is described as a three-dimensional value and the classification of such error components is proposed. Within the framework of a three-dimensional model, the structure of a saturating toolkit total error is systematized. Properties of one component – the hue non-uniformity of conversion – were studied for 24 graphic software packages. Its peculiarity that is critical for the certain graphic information integrity aspects in the course of saturation-contrast transform was revealed. Anticorrelation of the hue non-uniformity with the previously found brightness shift was detected. As a result, the investigated software product does not guarantee the adequacy of color saturation-contrast control in image analysis tasks. The last does not allow these packages to be used within forensic expertise anyway. Results of analysis for the software package being devoid of both errors (the hue non-uniformity and the brightness shift) are presented. So the earlier announced system requirements to maintain the initial color hue and color brightness are to be supplemented by the uniformity requirement for color saturation conversion process itself.

    Keywords: Software metrology, color saturation transform, saturations’ contrast, contrast enhancement errors, graphic information integrity, expert applications

  • Investigation of the possibility of using different types of interferometers in an automated control system for Earth orientation devices

    The article discusses the requirements for automated control systems in the production of Earth orientation devices. Various types of interferometers are analyzed for use in an automated control system for the manufacture of optical instruments for orientation of spacecraft on the Earth. An overview of the most common interferometer models is given, the characteristics and features of their schemes, development trends and manufacturers are discussed in detail. A comparison was made of the parameters of a number of imported and domestic interferometers suitable for use in an automated control system. The advantages and disadvantages of interferometers according to the schemes of Jamen, Mach-Zehnder, Sagnac, Michelson and Fizeau are considered. The Jamen interferometer was invented for the first time in 1856, to measure small refractive indices of gases. The Mach-Zehnder interferometer was developed on a similar principle, its main feature is that the beams of the rays obtained can be separated at a sufficiently large distance using a semitransparent mirror. In 1913, the Sagnac interferometer was invented; in its design, the light is divided by a semitransparent plate-divider into two beams, which propagate in a circle and are reduced by mirrors back to the divider. Albert Michelson in 1890 proposed an interferometer scheme, the basis of which is a light-splitting mirror. One of the most common is the Fizeau interferometer scheme, proposed in 1868. In this type of device, interference occurs in the gap between two reflecting surfaces. Based on the parameters of the problem under study, the choice in favor of the interferometer configuration according to the Fizeau scheme is justified. Interferometer OptoTL-60/125 from LLC "Optical laboratory" meets all the requirements.

    Keywords: automated control system, laser interferometer, Fizeau interferometer, optics, photonics, optical production, interferometry

  • Comparative evaluation of the methods of an ultra-narrowband packet of discrete frequencies radiation formation

    The paper presents a comparative assessment of the methods for generating radiation in the form of a two and three-frequency symmetric packet of discrete frequencies, both traditional on the basis of the Mach-Zehnder modulator operating at various operating points, and the author's on the basis of tandem amplitude-phase modulation. The generated emissions are special cases of an ultra-narrowband packet of discrete frequencies used to construct radio-photonic vector analyzers. Based on the results of computer simulation of the shapers in specialized software, a qualitative and quantitative assessment of the purity of the generated radiation is given, which confirms the results obtained for mathematical models and their adequacy to the described physical processes.

    Keywords: modulation of optical radiation, ultra-narrowband packet of discrete frequencies, Mach-Zehnder modulator, tandem amplitude-phase modulation, electroabsorption modulator

  • The concept of microwave photonic vector analyzers based on an ultra-narrowband packet of discrete frequencies

    The paper presents the concept of constructing microwave photonic vector analyzers of a new type based on an ultra-narrowband packet of discrete frequencies, formulated as a result of a comparative analysis of existing methods for constructing optical vector analyzers.

    Keywords: optical vector analyzer, microwave photonics, microwave photonic vector analyzer, modulation of optical radiation, ultra-narrowband package of discrete frequencies

  • Simulating of an optical vector analyzer with high-resolution and high-accuracy based on optical double-sideband modulation and stimulated Brillouin scattering

    The article discusses an optical vector analyzer with high resolution and high accuracy based on optical double-sideband modulation and stimulated Brillouin scattering. A model of an optical vector analyzer is presented.

    Keywords: optical vector analyzer, double-sideband modulation, stimulated Brillouin scattering, fiber Bragg grating with phase shift, simulation, Optisystem

  • Investigation of the possibility of simulating the optical characteristics of naturally aging leaves

    This article presents and investigation the diffused reflection spectra of light from designed green pigments based on chromium(III) oxide, obtained by pyrochemical method by thermal decomposition of ammonium dichromate powder and hydrolytic method from chromium(III) sulfate in water-ammonia solution, as well as zinc oxide doped with cobalt, which are obtained by pyrochemical Sol-gel citrate method, with different levels of cobalt doping, obtained on the basis of silicone with the addition of obtained green pigments based on chromium(III) oxide), some commercial samples of PLA plastics are green in color and from naturally aging green leaves of grasses, trees and shrubs typical of areas with a transitional climate from mild continental to subtropical according to the Köppen classification. A comparative analysis of their diffuse light reflection spectra was performed to determine whether it is possible to partially simulate the diffused light reflection spectra from naturally aging green tree leaves with non-organic pigments or functional materials. Based on the analysis conducted, it is concluded that the studied commercial samples of green PLA plastics are categorically not suitable for simulating the spectra of diffused light reflection from green leaves. However, it is possible to create functional composite materials that can approximately imitate the spectra of diffused light reflection from green leaves of grasses, trees and bushes.

    Keywords: spectroscopy, diffuse reflection, functional materials, pyrochemical sol-gel citrate method, hydrolytic methods, chromium (III) oxides, inorganic pigments

  • Reconstruction of structural images of endoscopic optical coherence tomography by taking into account speckle patterns

    In the presented work, a method of reconstruction of structural images in endoscopic optical coherence tomography based on taking into account speckle patterns by using the operations of morphological erosion and expansion is considered. The proposed algorithm for reducing the level of speckle noise to improve the quality of visualization in endoscopic optical coherence tomography was practically implemented in the LabVIEW environment. Distinctive features of the proposed algorithm are morphological processing of B-scans, filtering by convolution before morphological processing of B-scans, and multilevel filtering of A-scans and B-scans consisting of them. A series of computer experiments showed a stable increase in the signal-to-noise ratio and contrast of the obtained structural images when using the developed algorithm. The proposed algorithm for reducing the level of speckle noise in structural images can be used in medical technologies to visualize the internal structure of cavities and body tracts.

    Keywords: speckle noise, optical coherence tomography, endoscopic systems, structural image, morphological erosion, morphological dilation, speckle reduction, coherence probing depth

  • Traffic control system using phase shift fiber Bragg gratings

    The article uses a method of modernizing solutions for constructing vehicle monitoring models made using standard Bragg structures. The applicability of fiber Bragg gratings (FBGs) with structural defects such as phase shifts is carried out. This article proposes a fiber-optic sensor system (FOSS) based on FBG with a phase π-shift, which makes it possible to switch from optoelectronic interrogation methods to radio-photonic ones. The radio-photon approach is presented as an effective method for detecting vehicles in normal traffic. The principle of information signal formation when measuring vehicle parameters. This FOSS allows, on the one hand, to get rid of an expensive optoelectronic interrogator, on the other hand, it requires the construction of neural network models for its work to determine cars of different types and weights.

    Keywords: fiber bragg gratings, phase shift, distributed sensor networks, portable sensor, traffic density monitoring

  • Algorithm to control saturation contrast of digital images and its program realization

    The paper deals with virtual-optic image processing, particularly – with contrast enhancement, specifically – with control of color saturation contrasts in order to detect latent graphic information. The theorem of a hue invariance at color saturation through RGB-coordinates shift and its brightness restoration through RGB-coordinates proportional variation is proved. Meeting the corresponding requirements for analytical software tools, the original algorithm and program to enhance saturation contrasts were developed. The truncated brightness equation is presented. The possibility to optimize the speed versus accuracy of the conversion is laid. The program was successfully approved: a significant increase in the information content of the image was recorded. The efficiency of the created software product application to expert problems is demonstrated.

    Keywords: graphic information, color saturation, saturation contrast, contrast control, algorithm and program, latent images, expert applications

  • On the possibility of using optoacoustic methods for studying the properties of biological tissues (review)

    The optoacoustic effect used for imaging can provide improved spatial resolution and temperature sensitivity compared to other methods of non-invasive cytometry, thermometry, used during thermal therapy for safe and effective diagnosis. However, the accuracy of the described optoacoustic methods is reduced due to biological variability and heterogeneous composition of tissues. Optoacoustic spectral analysis is used to assess the morphological changes of red blood cells (for example, size / shape).

    Keywords: optoacoustics, optoacoustic signal, biofluid, oxygenation, hemoglobin, erythrocyte

  • Prospects for the application of the XPS in fire technical expertise

    The article describes the principles of the method of x-ray photoelectron spectroscopy. There is described a method for the possible application of the XPS method in fire-technical expertise. There ar given criteria for determining the type of short circuit on electrical products removed from the fire. Depending on the conditions of the occurrence of the circuit of the conductors changes their chemical composition. There are describe of the implementation of existing methods of analysis used in fire laboratories. There given a brief description of the main components of the time-of-flight spectrometer, including an x-ray tube, time-of-flight energy analyzer, and the principles of their operation. Application of the principle of aggregation of spectrometer elements makes it possible to simplify the adaptation of the method of X-ray photoelectron spectroscopy to solving problems in the field of fire safety. There is describe experimental technique in the author’s spectrometer.

    Keywords: X-ray spectrometer, x-ray tube, photoelectron spectrum, vacuum system, short circuit, fire-technical expertise, time-of-flight energy analyzer

  • Automatic calibration of nonlinearity of intensity in projection systems

    The article discusses the method of automatic elimination of nonlinearity in the registration of intensity in projection systems. Errors in the intensity recording affect the accuracy of phase measurement systems based on structured illumination of objects. Gamma-correction hardware cannot completely eliminate such distortions, since the type of inverse relationship may be a more complex function. The method is based on the projection of the ideal wedge and automatic determination of the intensity levels required for recording

    Keywords: optical measurement systems, structured lighting, profile detection, intensity, nonlinear distortion, digital image processing

  • The creation and properties of the phantoms of biological tissue containing nanoparticles

    Phantoms are an imitation of biological tissue. With the help of phantoms, it is possible to simulate the propagation of light in biological tissue. During any biophysical experiments there is a need for the constancy of the initial conditions of the experiment. The use of solid phantoms that do not degrade over time and under the influence of external factors is the Foundation for reliable results and repeatability of the experiment. The creation of phantoms of biological tissue containing fluorescent nanoparticles or nanoparticles with high absorption, and which correspond to specific mechanical or optical properties, is an urgent task. The paper describes the development, fabrication and characterization of solid tissue phantoms containing gold and upconversion nanoparticles. Optical and mechanical properties of phantoms are studied. The temperature range suitable for the use of samples as phantoms of biological tissue for laser thermolysis problems was revealed.

    Keywords: phantom, gold nanorods, luminescence, quantum dots, thermogravimetric analysis

  • Calculation of the efficiency of optical radiation input of DFB and VCSEL lasers into a glass integrated optical waveguide

    The efficiency of optical radiation input of semiconductor lasers of various types into an integrated optical ion-exchange buried waveguide in glass was calculated using optical circuits based on spherical, hemi-cylindrical and hemispherical lenses. Calculations were made by using the method of ray tracing. The single-mode waveguide, used in calculations, is the glass (type K-8) waveguide, made by ion exchange with subsequent burying. The results of the calculations indicate a low efficiency of optical radiation input when using single lenses. The use of a pair of microlenses (collimating and focusing) makes it possible to significantly increase the efficiency of optical coupling, which is 79% for a VCSEL laser. Efficiency of input is limited by a sufficient low aperture of the glass waveguide itself - 0.12. For more precise simulations the race tracing method with wave correction was used. The wavelength of optical radiation for calculations is 1.3 micrometer. The use of a single spherical and cylindrical lens has the advantage for it’s simplicity, but will lead to a serious loss of power in the optical system and, correspondingly, an increase of signal attenuation. This is partly due to reason that when using a single cylindrical or spherical lenses, according to the geometry of the calculations, the optical radiation will not be focused at one point, and essential aberrations take place. Efficiency of coupling with the help of two lenses is limited at first, by numerical apertures mismatch and, at second, partial energy transfer to the rings of Airy disk. The ion-exchange waveguide is suitable for coupling with VCSEL lasers for application in planar waveguide concentrators, etc.

    Keywords: integrated optics, optical waveguides, ion exchange in glass, VCSEL laser, ray tracing method, ZEMAX

  • The use of the modifier polyisobutylene to improve the efficiency of operation of greases

    The article presents the results of the use of viscous additives based on polyisobutylene to improve the performance of railway greases LZ CNII. It is established that the introduction of this type of additives into the dispersion medium of lubricants allows to increase their colloidal stability and tribological properties without deterioration of the operational parameters essential for the application of these lubricants.

    Keywords: plastic lubricant, friction, thickener, polyisobutylene, wear resistance, grease film, reliability

  • The evolutionary transformation of polarization of optical radiation based on weakly guiding waveguides in glass

    The new polarization integrated-optic scheme based on weak-guided waveguide in glass is proposed - the passive 90-degree convertor of linear polarization. The converter has the evoulution type of it working principle. Converter consists of four-layer waveguide, which includes ion-exchange waveguide in glass with high-index cladding film, having tapered thickness or (in another variant of converter) tapered width. The working principle of converter has been explained with mode analysis techniques. The calculations showed that in the small range of thickness (or width) of nano-scaled cladding film the second and third waveguide modes have nearly equal effective indices and hybrid structure of fields, and out of this range the same modes have the field structure of modes TM0 and TE1. The smooth (adiabatic) increase of waveguide cladding film thickness (or width) along it longitudional geometric axis means that such waveguide is a polarization converter, which transforms mode TM0 to mode TE1.

    Keywords: Integrated optics, polarization converter, optical waveguide, guided-wave mode

  • Layered two-dimensional-periodic absorbing structure of the optical range

    Described trends in the application of two-dimensional-periodic absorbing structures in optical and THz range. The results of calculation of the scatter and reflection of multilayer structures. Designed optimal parameters of the structures to monitor the greatest effect absorption.

    Keywords: resonant absorption, plasmons, reflection coefficient, diffraction gratings, periodic structures

  • Optics of immersion environments in the technology of processing of diamonds

    The use of chalcogenide glass as immersion environments on the partitioning in the production of cut diamonds. The work can be useful for specialists in the diamond businesses.

    Keywords: optics, optics of anisotropic media, immersion medium, not faceted diamonds, recognized by optical defects in diamond, chalcogenide glass, the spectral characteristics of chalcogenide glass, the visualization system

  • Physico-mathematical modeling of multi-step technology processes of single-mode waveguide fabrication in glass K-8 by ion exchange technique

    Physico-mathematical modeling of multi-step processes of waveguide fabrication in glass K-8, based on the combined, solution of two-dimensional nonlinear diffusion equation, electrostatic equation and wave equation has been made. The diffusion equation was solved by application of implicit finite-difference two-layer Crank-Nicolson scheme with appropriate boundary conditions for each step of technology. The general case of three-step technological process is considered, including thermal ion exchange ”silver-sodium” in salt melt mixture AgNO3:NaNO3, electric field-assisted waveguide burial in salt melt NaNO3 and final step of glass substrate annealing. The technological conditions for the fabrication of single-mode waveguides, which have the size of mode field suitable for efficient butt coupling of waveguides with optical fibers at 1.55 micrometer wavelength, have been determined. The calculated mode size of waveguides is 10.6*9.5 um; the coupling efficiency with fiber is above 99%. Also the modeling of partially buried waveguide has been performed, where the field-assisted burial was made with the deposited mask covering the half-surface of ion-exchanged waveguide. Such waveguide has asymmetric distribution of refractive index and hybrid guided modes, and it may be the base of passive waveguide polarization TE-TM converters.

    Keywords: integrated optics, optical waveguides, ion exchange in glass, electrically stimulated migration of ions, the nonlinear diffusion equation, waveguide mode