Correlation optics at the single-photon level: device physics and quantum mechanics
Author(s):
William T. Rhodes;
Angela Maria Guzman;
Jean-Pierre Goedgebuer
Show Abstract
Optical engineers will need to know progressively more about quantum optics as they move into fields like quantum cryptography, quantum computing, and quantum teleportation. Intuition based in classical optics can sometimes serve the system designer well, but in some cases classical intuition conflicts with quantum-regime fact. This paper provides an introductory review to certain important aspects of quantum optics, such as the particle-wave duality of photons, field quantization, quantum states of radiation, particularly as they relate to the first- and second-order correlation processes that are important in distinguishing the quantum regime of light from the classical regime. It also presents the results of two preliminary quantum-regime analyses of devices important in the engineering of information processing systems that operate at the individual photon level, the electro-optic modulator and the acousto-optic modulator.
Topology of optical vortices spontaneous birth
Author(s):
Vyacheslav N. Gorshkov;
Anna N. Kononenko;
Marat S. Soskin
Show Abstract
A theory of optical vortex spontaneous birth in a propagating light beams with smooth wave fronts is presented. Two possible mechanisms of optical vortices birth (nucleation) are developed. The conditions of their realization are formulated.
Transmitting, destruction, and self-recovery of the optical vortices in low-mode fiber optical systems
Author(s):
Alexander V. Volyar;
Tatyana A. Fadeyeva
Show Abstract
It is considered the physical processes of the optical vortex self-recovery both after an ordinary fiber and inside the special fiber types. As a rule, a light field after the fiber has not steady structure but fast changes near a fiber end. The excitation condition may be chosen so that the noise vortices are annihilated and the work vortex is recovered. Besides, optical fibers having regular perturbation so as a spiral winding or a twisting can transmit the optical vortex without structural changes. It is those properties of fiber vortex systems that are studied in the given paper.
Spontaneous birth of optical vortices in a system of copropagating Gaussian beams
Author(s):
Marat S. Soskin;
Galina V. Bogatiryova;
Vyacheslav N. Gorshkov
Show Abstract
A possibility of nucleation of wave front singularities kind of vortex dipoles under combination of two smooth wave fronts with Gaussian amplitude distribution substantiated on the base of a parabolic equation is realized experimentally. Trajectories and space dynamics of a vortex dipole and its conversion are studied as the function of the propagation distance.
Interrelations of fine structure of the vector field and its averaged polarization characteristics
Author(s):
Alexey I. Mokhun;
Marat S. Soskin
Show Abstract
Interrelations of the fine structure of the vector field and its averaged polarization characteristics are considered. It is shown that space averaged Stokes parameters are defined by dispersion of the phase difference in its saddle points. The dispersion of phase difference and dimension of areas with considerable polarization changes are related with the averaged space between the nearest adjacent component vortices f the same sign. The results of computer simulation and experimental modeling are presented.
Computer simulation and physical modeling of self-converging optical traps
Author(s):
R. Brandel;
Alexey I. Mokhun;
Igor I. Mokhun;
I. D. Paliychuk
Show Abstract
The possibility of the self-converging optical traps formation on the base of elementary polarization singularities is considered. The principles of the formation of s-contours with optimal characteristics are formulated. The technique of creating of such field based on the computer-generated holograms is proposed. The results of computer simulation and experimental modeling are presented.
Birth and death events in topological multipole fields after emissions from an optical fiber
Author(s):
Yuri V. Egorov;
Alexei N. Alexeyev;
Oleg A. Shipulin;
Alexander V. Volyar;
Marat S. Soskin
Show Abstract
It is represented the experimental results confirming the existence of the optical vortices after a low mode fiber end, while there are no free optical vortices propagating along the fiber itself. In this case the vortices are as a rule coupled. The vortex pairs is shown to arise at some distance from fiber output and then they disappear after passing through some space section. This distance revealed to be controlled by means of the fiber excitation way. Though the optical vortices are born (annihilated) in pairs, at the same distance a single vortex may appear separately in the observation field, displacing other vortices at the infinity. This happens due to the interference energy conversion from one vortex to an other.
Modes of twisted fibers
Author(s):
Constantin N. Alexeyev;
Alexander V. Volyar
Show Abstract
The mode structure in weakly guiding twisted fibers is investigated. It is demonstrated that in the case of small pitch of twist in the model without the spin-orbit coupling modes of twisted fibers are almost pure circular vortices with suppressed mode dispersion. The influence of the spin- orbit coupling on mode structure in twisted fibers is discussed.
Optical vortex generation by optical wedge
Author(s):
Yana V. Izdebskaya;
Vladlen G. Shvedov;
Dmitry Kurabtzev;
Alexei N. Alexeyev;
Alexander V. Volyar
Show Abstract
It is experimentally and theoretically studied the generated vortex process by the optical wedge and the optical knife. After those optical transparencies it takes place the birth and death vortices events. By adjusting the slope angle of the transparency and the beam truncation depth, the Gaussian beam may be converted into the singular beam transferring a single vortex.
Computer processing of fiber-vortex sensor data
Author(s):
Tatyana A. Fadeyeva;
Dmitry Kurabtzev;
Alexander V. Volyar;
Marat S. Soskin
Show Abstract
It was considered three methods of the computer processing of the spiral interference pattern being the result of two field superposition: the field carrying over an optical vortex and scattered from the optical fiber with a field of a referent fundamental Gaussian beam. The revolving interference pattern was subjected to the computer processing and the coordinates of the spiral center and the parameter of the spiral curvature was defined. As a result of that it was chosen the most optical method and was found that optimal computer inaccuracy of measurements of spiral phase is 0.0115 rad.
Measurement of the orbital angular momentum of an optical beam with the help of space-angle intensity moments
Author(s):
Alexander Ya. Bekshaev;
Andriy Yurievich Popov
Show Abstract
An orbital angular momentum (OAM) of the optical beam is shown to be reflected in the special structure of its matrix of space-angle intensity moments. Considering the properties of these moments and their transformations, a conclusion has been made that any light beam with the OAM experiences a characteristic transverse shift during its interaction with a plane boundary or a diffraction grating. On this base, a method for the immediate measurement of the beam OAM is proposed. The simple experimental arrangement for such a measurement includes a self-collimating diffraction grating, a position-sensitive quadrant photodetector and a device for the beam rotation around its longitudinal axis.
Vortex soliton in parabolic optical fiber
Author(s):
Igor V. Dzedolik;
A. I. Dzedolik
Show Abstract
It is shown, that the vortex pulse may be transformed into the vortex soliton in the parabolic optical fiber, if the pulse power is more than the threshold value. The changes of the soliton phase are examined.
Vortex pulse interference
Author(s):
Igor V. Dzedolik;
S. N. Lapayeva
Show Abstract
The interference of the vortex pulse having passed through the optical fiber and basic Gaussian pulse is considered theoretically. It is shown that the interference figure depends on the phase shift of the vortex pulse is gained in the fiber under the exterior influence.
Spectral analysis of the device operators in polarization dynamics
Author(s):
Tiberiu S. Tudor
Show Abstract
The spectral analysis of the device (instrument) operators, as an alternative approach to the dynamical polarization phenomena, is presented by means of two examples of classical time-varying optical device: the electro-optical modulator with longitudinal effect in crystals of KDP and the rotating birefringent plate. The polarization-spectral structure of the modulated light is analyzed on this basis, in terms of spectral Jones vectors.
Peculiarities of vector coherent optical field formation
Author(s):
M. Y. Sakhnovskiy;
B. M. Timochko;
Miroslav T. Strinadko
Show Abstract
The real optical fields formed by the coherent beams are characterized by the certain distribution of intensity and polarization. The formation of such field is caused by presence in space of several coherent beams with various wave vectors and condition polarization. In research work the analysis of such fields in the determined plane of uniform coordinate system is carried out. It's shown that for the analysis of interferentional picture it's good to use three corners describing space position of the electrical vector in chosen coordinate system. We consider two limit cases: field homogeneous on intensity and with the certain polarizing distribution and its contrary one. The contrasts of the interferentional pictures for a number of characteristic directions of the electrical vector through ellipsometric parameters are determined. The conditions for registration and restoration of polarizing structure of the field in holography are determined.
Object field correlation properties as information carriers of image
Author(s):
Yuri N. Zakharov;
Evsey Yakubovich;
P. A. Khandokhin
Show Abstract
The registration of an autocorrelation function of an object field with the help of Fizeau interferometer was carried out in order to reconstruct an object field and derive the volumetric image without information redundancy. In result the obtained image corresponded expected.
Three-dimensional microscopy and measurement by phase-shifting digital holography
Author(s):
Ichirou Yamaguchi
Show Abstract
Digital holography means hologram recording by a CCD and image reconstruction by a computer. The conventional off- axis setup has limitations arising from much lower resolution of CCD than photographic materials. In phase- shifting digital holography employing an in-line setup complex amplitude at a CCD plane is directly detected by stepwise phase-shifting of the reference beam. The complex amplitude is then subject to Fresnel transformation to deliver complex amplitude in three-dimensional space. This method suppresses the zero-th and conjugate images completely and provides high quality of reconstructed images. In this paper basic procedure of the phase-shifting digital holography is first described. Then its applications to 3-dimensional microscopy is reported that is capable of numerical focusing and direct phase observation. Without any imaging lens we can attain resolution of a few micrometers. The second application is concerned with measurement of surface shape that takes the difference of phase distributions reconstructed from different incident angles of the object illuminating beam. This method has the same sensitivity as the conventional fringe projection but the evaluation is simpler and can also be used for deeper and smaller objects. Finally issues for practical applications are discussed.
Fourier approach to digital holography
Author(s):
Romulad Jozwicki
Show Abstract
Basing on the Huyghens-Kirchhoff's formula the relations between field distributions on the object and Fourier transform spheres with parameterized coordinates in the vector form are introduced. The application of the reference sphere transformation principle is proposed. The set of equations using Fourier transformation to determine the field distributions on various planes in the holographic image space is given. Simulating a complete holographic process some examples of the amplitude distribution determination are presented
Local optical characteristics of semiconductor surfaces
Author(s):
Pavel Tomanek;
Marketa Benesova;
Dana Kostalova;
Petr Letal
Show Abstract
Photoluminescence (PL), photoreflectance (PR) and photocurrent (PC) spectroscopic techniques have demonstrated to be helpful experimental methods to investigate the properties of bulk semiconductors, microstructures, surfaces and interfaces. We present near-field local PL, PR and PC spectroscopic study of semiconductor quantum structures using a technique of reflection Scanning Near-field Optical Microscope (SNOM) in combination with Nitrogen laser and tuning dye laser and with He-Ne laser. Reflection Scanning Near-field Optical Microscope (SNOM) employs an uncoated and/or Au-metallized single-mode fiber tip both as nanosource and a nanoprobe. In the illumination-collection hybrid mode, the first one serves to excite the semiconductor sample and the second one to investigate characteristics of the structure and to pick up the PL and PR intensity reflected from the sample. In the illumination mode, the nanosource illuminates locally the semiconductor structure, and excites the photoelectrons in the PC spectroscopy. This near-field device is applied for the diagnostics of the defects in semiconductor devices. Take opportunity of the high lateral resolution of the microscope and combine it with fast micro-PL, PR responses, it is possible to locate for instance defects in a multiple quantum well grown by molecular beam epitaxy. Near-field characteristics of measured quantities are also discussed.
Simple and compact ESPI system for displacement measurements on specular reflecting or optical rough surfaces
Author(s):
Rene Skov Hansen
Show Abstract
This paper presents a stable and compact speckle interferometer for doing out-of-plane displacement measurements on reflective as well as diffusely scattering object surfaces. The set-up is based on a nearly path length compensated interferometer of the Fizeau type and uses diffuse illumination of the object combined with a speckled reference wave. This combination eliminates the need of special optical components, and the interferometer can be built of commonly available components. The diffuse illumination wave is obtained by scattering coherent light from a diffusely scattering surface. The speckled reference wave is established by reflecting a part of the diffuse illumination wave from a glass plate placed in front of the object.
Holographic applications of As-S-Se inorganic resist
Author(s):
Sergey A. Kostyukevych;
Miroslav Vlcek;
Nadya L. Moskalenko;
Peter E. Shepeliavii;
Alexander V. Stronski;
Sergey V. Svechnikov;
Evgenie F. Venger
Show Abstract
The present paper is concerned with the investigation of imaging properties of As-S-Se media in application for fabrication of holographic optical security elements. Structural changes in such medica under the influence of external factors (exposure or annealing) were studied. Photo- and thermally induced structural changes were directly confirmed by Raman scattering measurements. Surface relief formation properties were investigated with the help of improved amine based solvents, which provided good surface quality. Various types of holographic security elements (HSE) were fabricated and their properties studied. Fabricated surface relief provided high values of diffraction efficiency. For example, diffraction efficiency of such elements as holographic diffraction gratings consisted up to 60 - 70% in non-polarized light. High quality polymer copies of the initial HSE were obtained.
Optical low-coherent interference profilometer with improved performance
Author(s):
Yuri V. Chugui;
I. V. Golubev;
Yu. D. Makashev;
Ye. V. Sysoev
Show Abstract
Profile measurement of the surface defects (with the depth of dozens of microns), based on the low-coherent interferometry, is discussed in this paper. The major challenge for production of such devices is selecting interference fields, which are used to determine the isolines of the defect depth. A direct way to find low- contrast interference fields in a large dynamic light range appears to be an extremely difficult procedure. We propose an effective interference fields localization technique based on the reference wave phase modulation that against others provides high measurement accuracy and reliability. The reconstructed 3D-image and depth isoline map of 50 micrometers deep defect on the metallic surface of the fuel element are also presented. The system for surface profile measurement with the following characteristics has been developed: surface reconstruction error is less than 2 micrometers , surface reconstruction range on depth is up to 10 mm.
Effect of negative imaging by an opaque screen
Author(s):
Peter V. Polyanskii;
A. D. Arkhelyuk
Show Abstract
The effect of negative imaging of an extended source of polychromatic radiation by an opaque screen is elaborated. It is shown that such imaging is of geometrical optics (shadow) nature rather than of diffraction one, as it was assumed earlier. On the base of the geometrical optics model, we define spatial domain behind an opaque screen where the negative imaging is realized, and determine the dependencies of the image parameters on the experimental conditions. Negative images are demonstrated for the first time, and the qualitative confirmation of the geometrical optics model is given.
Higher-order holographic associative memories and image processing
Author(s):
Peter V. Polyanskii;
Christina V. Fel'de
Show Abstract
The problem of holographic associative memory and image processing is treated with account of the higher-order components of a thin hologram's amplitude transmittance and its higher diffraction orders. It is shown for the first time that a far-field nonlinear hologram of a diffraction aperture read out by the stored signal or its part provides full-image reconstructions (associative responses) in all observable diffraction orders. This result substantially develops so-called 'quadric holography approach' establishing that only error-corrected complex-conjugate associative response at the minus-second diffraction order of nonlinearly recorded thin hologram of a diffuse object can be reconstructed. Proceeding from the Young-Rubinowicz model of diffraction phenomena, it has been substantiated and proved experimentally that the higher-order associative responses turn out to be contoured being the higher-order reconstructions of the Young's edge diffraction wave. Besides, it is shown that a near-field nonlinear hologram from a half-tone input signal (without a diffuser) provides self-imaging of the stored memory in the form of its conjugate image with the inverted contrast.
Small optical device for measurement of surface roughness
Author(s):
Vladimir Ya. Mendeleev;
Sergey N. Skovorod'ko;
Vladimir N. Porotov;
Konstantin Yu. Kim
Show Abstract
The device based on the reflectometric method is intended to measure surface roughness parameter Ra by means of comparison of light power reflected from a measured rough surface and light power reflected from standard rough surfaces with known Ra. The light power is measured in the specular direction for the normal incidence. The range of measured Ra is 0.05 - 1.3 micrometers . The device was tested in factory conditions for measurement of surface roughness of a roller during grinding. Values of Ra measured with the device were compared with the values determined with a profilometer. Difference between values Ra measured with the both devices was no more than 10%.
Formation of autocorrelation recall of small-sized objects
Author(s):
Mickolay M. Dominikov;
Miroslav T. Strinadko;
B. M. Timochko
Show Abstract
The paper deals with the technique of processing of speckle- frames of small-sized disseminating objects according to their isophots. Isophots of single contrast built for different intensity levels, result in redistribution of intensity in the maximum diffraction orders, that is in the area remote from low frequency, noise components. It allows adequately to perform the analysis and to define the microshape of an object.
Investigation of optical diffraction by Sierpinski's carpets
Author(s):
Maksimyak Alexander;
Rukhtin Vasil
Show Abstract
The results of a theoretical and experimental investigation concerning to some peculiarities of reproduction of the Sierpinski's carpets structure at the diffracted optical field are represented. The elements of Sierpinski's carpet is reproduced in the diffracted field. For the input fractal of the 4th level, image fractals of all levels from 1 to 3 are observed at the diffracted field, and the image is noised. The experimental results are shown to be in a good agreement with the ones obtained through computer simulation.
Statistics for partially developed speckles: the impact on speckle-based measurements
Author(s):
Steen Gruner Hanson;
Rene Skov Hansen;
Harold T. Yura
Show Abstract
The treatment of first- and second order intensity statistics of light scattered from surfaces not giving rise to fully developed speckles will be presented. Analytical expressions will be given for speckle size, first-order intensity moments and intensity variance within the framework of using the Huygens-Fresnel integral with the complete optical system included by the complex valued system ray ABCD-matrix. Various surface models will be presented, all being based on a Gaussian height distribution with various lateral length scale(s). For the sake of simplicity, only rotationally symmetric optical systems will be treated and no depolarization effects during scattering will be included.
New feasibilities for characterizing rough surfaces by optical correlation techniques
Author(s):
Oleg V. Angelsky
Show Abstract
New feasibilities are considered for optical correlation diagnostics of rough surfaces with different distributions of irregularities. The influence of deviations of the height surface roughness distribution from a Gaussian probability distribution on the accuracy of optical analysis is discussed. The possibility for optical diagnostics of fractal surface structures are shown and the set of statistical and dimensional parameters of the scattered fields for surface roughness diagnostics is determined. Finally, a multifunctional measuring device for estimation of these parameters is proposed.
Fractality of optical fields scattered by power-law-illuminated diffusers
Author(s):
Jun Uozumi
Show Abstract
Some recent development on the properties of speckle intensity distributions that have fractal properties are presented. First, computer simulations are discussed for speckles produced by power-law illuminated diffusers with a wide range of the exponent 0 < D < 3 for the power function. By the simulation, the previous theoretical prediction for 1 < D < 3 is confirmed, and new results are found for D <EQ 1. Next, axial correlation property in the Fresnel diffraction region of the power-law illuminated diffuser is discussed on the theoretical and experimental basis. It is theoretically shown that the axial correlation function obeys the power function with the exponent of D - 2, which is subsequently confirmed by experiment. Finally, a method for producing fractal speckles in the image plane of a scattering object is proposed. Such speckles are actually generated and their power-law correlation behavior is demonstrated experimentally.
Speckle correlation technique as applied to structure analysis of multiphase systems with spatially separated components
Author(s):
Pavel V. Zakharov;
Dmitry A. Zimnyakov;
V. Trifonov
Show Abstract
Speckle correlation diagnostics was used to study non- stationary multiple scattering multi-phase systems with spatially separated components on the instance of porous media in the course of liquid-phase evaporation. We propose a phenomenological model in which the local interfaces between air-filled and liquid-filled spaces in the probed medium act as an ensemble of the elementary dynamic scatters. The motions of local interface boundaries in such a scattering coherently illuminated system cause the dynamics of speckle patterns, and their decorrelation rate is related to mass transfer rate in the porous medium. Thus, correlation or spectral analysis of the speckle dynamics allows us to evaluate structural characteristics of such an object under given evaporation conditions. In this paper the results of experimental study of sequences of speckle images for model porous media (paper) are compared with computer simulation of irreversible growth. Possible applications of speckle correlation technique for porous media structure diagnostics in industry, biology and medicine are discussed.
Experimental study of a reason for depolarization of laser light scattered from a rough surface
Author(s):
Vladimir Ya. Mendeleev;
Sergey N. Skovorod'ko
Show Abstract
The study is carried out for a unidirectional rough steel surface with rms roughness of 1.77 micrometers and rms slope of roughness of 0.135 rad. The degree of depolarization of scattered laser light with wavelength of 0.6328 micrometers was measured with a polarometer in the specular direction in the angular range of 30 - 80 degree(s). For laser light linearly polarized at a 45 degree(s) angle to the plane of incidence, the dependence of the measured degree of depolarization on angle of incidence has one maximum equal to 0.1 and an angle of incidence corresponding to the maxima is 70 degree(s). It is found experimentally that the reason for the measured depolarization is spatial variations of the azimuth and the ellipticity of the fully polarized scattered light within a polarometer aperture. Computer simulation of the scattering from a one-dimensional rough surface satisfactorily describing the dependence of the measured degree of depolarization on angle of incidence up to 70 degree(s) inclusive shows the single scattering makes the main contribution to the dependence of the measured degree of depolarization on angle of incidence.
Computerized simulation of sharp properties of photopaper
Author(s):
Oleg N. Kozakov
Show Abstract
The determination of the modulation transfer function of a photographic paper assumed the examination of the absorption process and light scattering in multilayer system: the protective layer - the emulsion layer - the barytes layer - the paper base. Special difficulties appear while examining the above-mentioned processes in the paper base that has to do with its anisotropy composition and, consequently, by spatial non-isotropy of its optical parameters. In this work it is shown that the usage of the statistical simulation method (Monte-Carlo method) makes it possible to by-pass the stated problem by the introduction of the point spread function of the paper base, which is possible to determine experimentally. Here are given the results of the modulation transfer function of a definite photopaper with a medium size of emulsion microcrystals (d equals 0.32 mcm).
Estimation of the polarization performances of a polydisperse medium with dynamically varying geometrical optic parameters
Author(s):
A. D. Arkhelyuk;
L. I. Podkamen
Show Abstract
Method of using the matrix method optics of light-scattering media for research the polarization characteristics of objects with dynamically varying geometrical optic parameters is described in this work. The results of measurings the Mueller matrix components of nematic liquid crystal (NLC) during the activity of electrical impulse are given. The character of transformation matrix (MT) and light scattering matrix (LSM) symmetry of exploring medium are determined. General analysis of nonzero components time dependencies of NLC Mueller matrix is given. The possibility of using the electrocontrollable liquid crystal as the model object for exploring the influence of the shape, size and orientation of nonspherical particles on the size of their Mueller matrix components is noted.
Fractal dimension of rough surfaces
Author(s):
Alexander V. Kovalchuk
Show Abstract
Does a rough surface have a random, fractal or multifractal heights distribution? The problem is studied by calculation of dimension spectra of both sample rough surfaces and elementary distributions.
Light scattering by Brownian particles
Author(s):
Alexander P. Maksimyak
Show Abstract
Light-scattering by the ensemble of Brownian particles is simulated and experimentally modeled. It has been shown that temporal stochastization of the scattered radiation field, in contrast to spatial stochastization of this field, keeps the fractal properties of the particles movement. Empirical diagnostics interconnections have been found between the fractal dimension and correlation exponent of the scattered radiation intensity, on the one hand, and the parameters of light-scattering medium, on the other hand.
Angular conditions of regular reflection detection
Author(s):
V. G. Zhytaryuk
Show Abstract
Angular dependencies of mirror luster detection in radiation reflected from a rough surface are investigated in a function of a root-mean-square (RMS) deviation of the height from a mean surface line. The difference between theoretical and experimental outcomes is detected. It is shown, that the metal coating of surfaces distorts the experimental outcome.
Photorefractive effect in terbium gallium garnet
Author(s):
I. Amin;
B. Sugg;
Martin Fally;
Romano A. Rupp
Show Abstract
Terbium gallium garnet is an interesting representative of the family of rare-earth garnets. In these crystal we have observed a photorefractive effect. This effect is probably linked to the light-induced dichroitic and photochromic behavior of this crystal. Using Kramers-Kronig-relations an estimation shows that the light-induced absorption changes can explain the observed refractive index changes. The observation of holographic writing with orthogonally polarized beams may by attribute to orientationally non- equivalent centers, which become anisotropic by the absorption of light after illumination. Yet, the nature of these centers is unclear. Further studies are already under way to clarify this point.
Magneto-optical correlation of the exciton series
Author(s):
Bohdan M. Nitsovich;
C. Yu. Zenkova;
O. V. Derevynchuk
Show Abstract
A theory of exciton light absorption in inorganic semiconductors with an arbitrary number of hydrogen-like exciton series levels has been suggested. The specific character of the behavior of the exciton-phonon interaction function for different levels of the series in the whole region of the phonon quasimomentum variation has been analyzed in detail. The influence of the weak magnetic field on the energy position of the exciton excitation levels has been investigated. It is shown that there is a full correlation between the bands of magneto-optical and exciton absorption.
Interaction of excitons with optical phonons in layer crystals
Author(s):
Bohdan M. Nitsovich;
C. Yu. Zenkova;
N. K. Kramar
Show Abstract
The investigation is concerned with layer crystals of the GaSe, InSe, GaTe, MoS2-type and other inorganic semiconductors, whose phonon spectrum has a great number of peculiarities, among them the availability of low-energy optical phonons. In this case the dispersion of these phonons can be essential and vary in character. The mass operator of the exciton-phonon system and the light absorption coefficient for different dispersion laws of optical phonons have been calculated. The influence of the sign of the phonon 'effective mass' on the exciton absorption band of layer crystals, which causes the opposite in sign dynamics of the absorption maximum shift, and the change of the absorption curve asymmetry have been determined.
II-VI compounds wide-band barrier detectors of He-Ne laser
Author(s):
V. P. Makhniy;
V. E. Baranjuk;
Mikhail M. Slyotov;
O. V. Stets
Show Abstract
The basic parameters and characteristics of surface barrier and heterojunction photodiodes that contain a layer of cadmium telluride with an isovalent impurity are examined. The role of the isovalent impurity in the magnification of the temperature and radiant resistance of the detectors is analyzed.
General switching kinetics in optical bistable systems
Author(s):
Yurij V. Gudyma
Show Abstract
The kinetics of switching in nonequilibrium bistable systems is studied. It is shown that different dynamical states for the traveling wave front of used generalized parabolic model are the phase states. The latter are described on the phase transitions' language.
Acoustic Cotton-Mouton effect in iron borate
Author(s):
M. B. Strugatsky;
K. M. Skibinsky;
V. V. Tarakanov;
V. I. Khizhnyi
Show Abstract
Dependence of the amplitude of transverse sound passed through a basal plate of easy-plane weak ferromagnet FeBO3 on a magnetic field H, parallel to the plate is investigated in experiment at T equals 77 K. The phenomenon is caused by magnetic birefringence of transverse sound, being the analog of Cotton-Mouton optical effect. In acoustics this effect is associated with magnetic additions appearing in elastic modules upon transition form a paramagnetic phase to an antiferromagnetic one.
FeBO3:NI monocrystals: photoinduced magnetic effects and synthesis
Author(s):
M. B. Strugatsky;
S. V. Yagupov;
A. Ya. Khrenov
Show Abstract
Monocrystals of Iron Borate, doped by nickel, FeBO3:Ni, have some extraordinary peculiarities. Domain structure of such crystals at room temperature is analogous to that of pure FeBO3 crystals. At temperature lower than 130 K, stripe domain structure with period approximately 50 micrometers appears. Light ((lambda) equals 0.8 divided by 1micrometers ) induces uniform movement of the substructure. One more peculiarity of FeBO3:Ni crystal is photoinduced magnetic memory existence. Method of synthesis of high quality FeBO3:Ni samples are discussed.
Light- scattering studies of blood sedimentation
Author(s):
Bronislaw Grzegorzewski;
E. Kowalinska
Show Abstract
We present the result of investigation of blood sediment formation with the use of three different optical techniques. The angular dependence of scattered light intensity, transmitted light intensity across the sediment's layer and correlation of speckle intensity fluctuations were measure. Two characteristic time periods of the sedimentation process are demonstrated. In the first period three phases can be distinguished: the plasma, the phase of diffuse erythrocytes and the phase of already formed aggregates. In the second period the phase of the diffuse erythrocytes disappears. The results support the hypothesis that a phase transition is associated with the blood sedimentation process.
Doppler and speckle methods for diagnostics in dentistry
Author(s):
Sergey S. Ulyanov;
Alexander V. Lepilin;
Nina G. Lebedeva;
Alexey V. Sedykh;
Natalia A. Kharish;
Yulia Osipova;
Alexander Karpovich
Show Abstract
The results of statistical analysis of Doppler spectra of scattered intensity, obtained from tissues of oral cavity membrane of healthy volunteers, are presented. The dependence of the spectral moments of Doppler signal on cutoff frequency is investigated. Some results of statistical analysis of Doppler spectra, obtained from tooth pulp of patients, are presented. New approach for monitoring of blood microcirculation in orthodontics is suggested. Influence of own noise of measuring system on formation of speckle-interferometric signal is studied.
Wavelet analysis in two-dimensional tomography
Author(s):
Dimitry N. Burkovets
Show Abstract
The diagnostic possibilities of wavelet-analysis of coherent images of connective tissue in its pathological changes diagnostics. The effectiveness of polarization selection in obtaining wavelet-coefficients' images is also shown. The wavelet structures, characterizing the process of skin psoriasis, bone-tissue osteoporosis have been analyzed. The histological sections of physiological normal and pathologically changed samples of connective tissue of human skin and spongy bone tissue have been analyzed.
Spectral OCT techniques in eye imaging
Author(s):
Andrzej Kowalczyk;
Maciej Wojtkowski
Show Abstract
This contribution presents examples of images of eye in vitro obtained by spectral optical tomography (OCT). Particular interest was focused on obtaining clear images of the corneo-scleral angle and images of fundus which are both essential for diagnosing and planning of a treatment of glaucoma.
Absorption spectral analysis of proteins and free amino acids in Pleurotus ostreatus fruiting body extracts
Author(s):
S. Kostyshyn;
I. Gorshynska;
S. G. Guminetsky
Show Abstract
The paper deals with the results of spectrophotometric studies of the extracts of Pleurotus ostreatus fruiting bodies, grown in natural conditions in different habitats of Chernivtsy region, in the spectral interval of 215 - 340 nm. It is shown that the samples reveal considerable difference both in free amino acid content and reserved protein content of albumins, globulins, prolamins, glutelins.
Light field scattered on bovine eye lens nucleus
Author(s):
Volodimir M. Rudeichuk
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The angular intensity distribution of light scattered on thin section of eye lens nucleus for the set of 27 bovine lenses with various wet weight is investigated in this paper. It is shown that the intensity distribution is the power function of scattering wave vector. The value of power function exponent increases during the wet weight increase. The random density fluctuation theory is used for scattering elements parameters evaluation.
Automative morphome analysis of medical-biological images
Author(s):
Vasyl P. Pishak;
K. B. Tymochko;
O. P. Antoniuk
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The morphological analysis of medical-biological images is investigated in this article. The developed software allows to calculate the morphometric parameters of histological cuts, the bases of their calculation and statistic processing are given here, using different approaches to mathematical processing.
Chronorhythm peculiarities in the presence of a stochastic exterior agent
Author(s):
Vasyl P. Pishak;
Taras N. Boychuk;
B. M. Timochko;
Miroslav T. Strinadko;
Katerina B. Timochko;
Marina M. Strinadko
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It is common to biological systems to have periodical changes of functional parameters. There are chronorhythms that correlate with periodic exterior agents, for example circadian rhythms and diurnal gyration of the Earth etc. Chronorhythm observations of the actual objects have shown the presence of additional rhythms in biosystems, which frequencies do not correlate with sync exterior oscillations. In the research work the analysis of the chronorhythm origin in biosystems, as the reaction to the noise perturbation is conducted. It's shown that the random perturbation can reduce the appearance of a quasiperiodic damping rhythm.
Concentration measurement of lysosome enzymes in blood by fluorimetric analysis method
Author(s):
Marina M. Strinadko;
Elena M. Strinadko
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The diagnostics of heritable disease series and sugar diabetes, myocardial infarction, collagenosis and kidney diseases widely uses the measurement of lysosomic enzymes in blood. In the present research work the definition procedure of concentration (beta) -glucuronidase with the help of fluorimetric analysis is offered, which allows using microamounts of biological fluids and samples with low enzyme activity which is especially important in paediatric practice. Due to the sharp sensibility of fluorimetric analysis and high speed of luminescent reactions the procedure gives an opportunity to obtain the result in the minimum terms as well as the use of small amounts of reaction mixture. The incubation in large dilution leads thereby to the elimination of influence of endogenic inhibitors and activators.
Correlation method of electrocardiogram analysis
Author(s):
Marina M. Strinadko;
Katerina B. Timochko
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The electrocardiograph method is the informational source for functional heart state characteristics. The electrocardiogram parameters are the integrated map of many component characteristics of the heart system and depend on disturbance requirements of each device. In the research work the attempt of making the skeleton diagram of perturbation of the heart system is made by the characteristic description of its basic components and connections between them through transition functions, which are written down by the differential equations of the first and second order with the purpose to build-up and analyze electrocardiogram. Noting the vector character of perturbation and the various position of heart in each organism, we offer own coordinate system connected with heart. The comparative analysis of electrocardiogram was conducted with the usage of correlation method.
Polarization visualization of two-dimensional tomography of biotissues
Author(s):
Yuriy A. Ushenko
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The fractal nature of the majority of biological tissues and intensive development of laser diagnostics in biology and medicine are stimulate an interest to creation of new optical methods of diagnostics and analysis of properties of biological fractals. The present paper is dedicated to investigation of polarization properties of cross layers of bone and myometry tissues.
Laser measurements of crystal optical properties of bioliquids
Author(s):
Alexander G. Ushenko;
A. V. Kuritscin
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The object of this research is to study the complex of the polarization parameters of the field of scattered laser radiation by means of the system of the formed blood elements of man. The following problems were solved - study of polarization statistics of laser biospeckle fields of human smear.
Pathogenic changes of dispersion and contrast of coherent images of biotissues
Author(s):
Olga V. Pishak
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The paper presents the results of polarization-correlation investigation of multifractal collagen structure of physiologically normal and pathologically changed tissues of women's reproductive sphere and of skin. The technique of polarization selection of coherent biotissues' images with the following determination of their autocorrelation functions and spectral densities is suggested. The correlation-optical criteria of early diagnostics of pathological changes' appearance of myometry (forming of the germ of fibromyoma) and of skin(psoriasis) are determined. The suggested paper is directed to investigation of the possibilities of pathological changes of biotissues' morphological structure by means of determining the polarizationally filtered autocorrelation functions (ACF) and corresponding spectral densities of their coherent images.
Use of laserotherapy in multimodality treatment and prevention of obstetric pathology
Author(s):
Antonyna A. Dudchenko;
Olexander M. Yuzko;
Iryna M. Marynchyna;
Oksana M. Rotar
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The purpose of our research was an analysis of the influence of laserotherapy in the process of treating late gestoses in gravidas, as well as preventing complications following cesarean section. An improvement of the state of the gravida and fetus was detected according to the findings of the disease pattern, coagulogram and cardiotachography. We want to demonstrate the positive effect of laserotherapy which was carried out with the purpose of prophylaxis on the course of the postoperative period in parturients. The results of observations is the following: pyo-septic complications reduced by 14.3%.
Laser polarimetry: possibilities in diagnostics of the uterine tube functional condition
Author(s):
V. M. Znak;
O. P. Peresunko;
O. G. Ushenko
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Inflammatory processes of the uterine adnexae is considered to be the most spread disease of the female sexual organs. Patients with inflammatory diseases of the female sexual organs constitute 60 - 65% among ambulant patients and about 30% among patients treated in the hospitals. In Ukraine from year to year a number of patients having been operated on serous adnexitis increasis. To find objective criteria to perform surgery in these pathological cases remains an important problem of the gynecological practice. Existing highly informative diagnostic methods - sonography, transvaginal echography, computer tomography - do not allow to follow the effectivity of therapy as they are static by their nature. By means of them it is impossible to determine the system functional state, to follow its reaction-response to treatment.
Activation energy of thermal fixing in LiNbO3: a comparative study
Author(s):
Mostafa A. Ellabban;
Gabor Mandula;
Romano A. Rupp;
Martin Fally;
E. Hartmann;
Laszlo Kovacs;
K. Polgar
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The activation energy of thermal fixing is determined in congruent and nearly stoichiometric lithium niobate crystals doped with manganese or iron, respectively. Three different techniques were employed: two-wave mixing, holographic scattering and DC conductivity measurements. A comparison between the three techniques is made and the possible reasons for the discrepancy in the values of the activation energy are discussed. Holographic techniques have the advantage of being contactless methods by which problems coming from electrodes effects are ignored. The holographic scattering technique is much simpler than two-wave mixing technique and gives the same results at high density of the compensating ions. At low free ions concentration it is an ideally sensitive technique to detect the possible dependence of the compensation time constant on the spatial frequency and to determine the concentration of free ions that are responsible for thermal fixing.