Some manifestations of the fractal-like behavior of speckle intensity fluctuations observed in quasi-elastic light scattering experiments with various optically inhomogeneous dynamic media are discussed. Following examples of scattering systems, which induce these fluctuations with fractal properties, are considered: moving random fractal amplitude and phase screens illuminated by broad collimated and sharply focused probe beams, single-scattering ensembles of Brownian particles, multiple scattered disordered media with stochastic or regular motions of scattering particles. Experimental results obtained with multiple scattering dynamic model media such as water suspensions of polystyrene spheres are presented.

Some peculiarities of the electromagnetic waves propagation in photonic band gap structures are considered. The wave phenomena at the edge of band gaps of 1D structures stimulating the nonlinear processes are described. Some examples of unusual optics laws in 2D structures are given.

The obtainment of stable solutions of inverse problems of studying the disperse composition of suspensions using effects of elastic light scattering were discussed. Versions of a regularization of solving the inverse problems of the spectroturbidimetric method were considered, taking into account unavoidable restrictions on the scope of the necessary prior data for particles and on the width of the spectral interval for real synthetic and biological disperse systems. Possibilities for increasing the number of particle parameters determined in a single optical experiment were analyzed. They were shown to be provided by the use of effects of the orientation ordering of a system on combination of capabilities of the methods of spectroturbidimetry and electrooptics, using bacterial cell suspensions as an example.

A new Two-Beam-Propagation Method algorithm for simulation of Second Harmonic Generation (SHG) process in planar optical waveguides is presented. The model accounts for an evolution of two beams propagating simultaneously: the fundamental and the second-harmonic one. Physically, the model consists of a separation of the propagation step and the nonlinear phase and amplitude compensation step. Mathematical formulation of the model is reported and some of its special features are discussed. The method can be easily generalized to investigated SHG processes in optical guides made from media with gain and/or loss. Also other nonlinear wave interactions such as self-phase modulation and cross-phase modulation can be dealt with using the method.

The theory of interferometric method of determination of vector components of relative displacements of two diffusers has been presented. Comparison of this method with the method of holographic interferometry has been made. The common nature of phenomena, on which both methods are based has been shown. The data of experiment, carried out for the verification of theory have been presented. A good agreement between theoretical and experimental data has been obtained.

We performed comparative analysis of numerical integration algorithms for original non-linear differential equations to elucidate their contribution to deterministic chaos behavior in the two gyro target signal. The analysis was based on the mathematical model of thermal drift for a fiber optical gyro with thermal control system represented by Peltier thermocouple. Feigenbaum universal constants as other deterministic chaos characteristics values were calculated with use of various numerical algorithms.

The influence of parameters of external optical feedback on the character of autodyne signal of semiconductor laser has been investigated. For harmonic and non-harmonic mechanical vibrations the possibility of restoration of interference signal function for autodyne system has been shown.

Experimental study of evolution of correlation exponent of intensity fluctuations in the case of transition between the partially developed and fully developed speckle fields is presented. Also the influence of scattering mode on the correlation properties of intensity fluctuations is investigated. Correlation exponent may be considered as the generalized parameter for the characterization of structural peculiarities of scattering objects.

New radiophotoluminophores are used for x-ray microscopy. The material provides the resolution 2 micrometers and dynamic range of registration equal to 10⁴. Some problems of using luminophores in rentgenography of biological objects are discussed. The examples of the images are given.

The dynamics of spontaneous cooperative emission in a cavity was investigated by numerical solution of semiclassical Maxwell-Bloch equations without slowly varying envelope approximation (in spatial variable). The dependencies of the pulse parameters on the resonator characteristics under condition of high phase relaxation of active medium are discussed.

This paper deals with the problem of calculating the polarization and spatial characteristics of laser radiation scattered by the eye tissues. Multiple scattering effects simultaneously with the degree of near order for scattering particles were taken into account.

The effect of movable charged dislocations in an ionic crystal upon scattering of electromagnetic radiation is studied. Cross sections for radiation scattering for different directions of incident radiation are determined. It is shown that cross sections depend on parameters of dislocations, in particular, on the dislocation velocity. A relation allowing the dislocation velocity in the scattering crystal to be determinated from the intensity of the central maximum spot of the scattering pattern observed is derived.

The problems of neutral atom beam formation and its application to the microelectronic manufacturing are considered. The plant using the focused neutral atom beam is presented. This high-vacuum plant is designed for complex CIP's processing. The scheme of this plant is given. It is divided into the following sections: atom generation, beam preparing, its structuring, compression, and surface treatment. The preparing section is described in detail. The beam is controlled by laser radiation resonant to basic transition in the atom absorption spectrum. The plant forms precisely structured low-temperature atom beams and controls atom density distribution in flow by rather simple projective methods. It allows discussing the possibility of the new, effective and high-automated manufacturing and analysis of micro-object surfaces. Resolution of the suggested method of treatment is proved to be limited only by characteristics of the equipment used. Calculation shows that at modern level of laser technique the spatial resolution of such a process can reach about 10 nm. The resolution of surface analysis is evaluated to be about 1 nm. Probable applications of the presented new technological process for integrated manufacturing, analysis and in-line reconstruction of the IC of super high integration by methods of liquid-free in-situ processing are considered.

Coherent optical time, frequency and heterodyne domain methods of dynamic parameters diagnostic of microwave transistors are discussed. Possibilities of optoelectronic and electrooptic station at the probing by picosecond pulses using mode-locked laser are considered. Peculiarities of microwave modulation of injective heterolaser and MESFET dynamic photoresponse are discussed. The determination of microwave transistor gain and noise coefficients using laser heterodyne methods at the probing of the active area drain- source is shown.

The main concepts of optical wave propagation in periodic structures are reviewed. A new method, named as `method of long lines' in optic calculations, is proposed. This method may be successfully employed to calculate either static or dynamic periodic structures with complex refraction index. Variation of wave interaction in dynamic periodic structures (acoustooptic interaction, scattering at metal- semiconductor-metal interface) is also given adequate consideration.

A new line of approach in gyroscopic theory is realized--it is the research of temperature disturbed nonlinear gyroscopic systems in view of probable initiation deterministic chaos phenomenon. A new nonlinear mathematical model for thermal drift of one the most of temperature- sensitive inertial sensor, i.e. a fiber-optical gyroscope equipped with a reversal thermocontrol system based on Peltier's thermocouples has been constructed and investigated by analytical and numerical techniques. Deterministic chaos generation in target signal (thermal drift of gyro) was demonstrated to be probable under a combination of system parameters together with external harmonic temperature perturbation. Computer experiments have been carried out, deterministic chaos criteria have been tested with respect to the autocorrelation function forms, power spectrum, Poincare's section, correlation dimension, Kolmogorov's entropy values and universal Feigenbaum's constants. Main possible scenarios for transition from regular behavior of system to deterministic chaos are analyzed, deterministic chaos areas have been built as functions of disturbances and system parameters.

Based on earlier work on Toda rings we propose here a model for energy-rich excitations in molecules. Localization of energy may be due to the fusion of solitons at soft springs imbedded into a ring of hard springs. In thermal equilibrium an optimal temperature region exists, where the potential energy is concentrated at the soft sites. The energy distribution, the autocorrelation function and the spectrum of the forces is studied.

General properties of super-radiance--cooperative spontaneous emission of multi-atomic systems are explained on the basis of some simple models. First we consider spontaneous emission of two atoms separated from each other by a distance less than the wavelength. Then the kinetics of super-radiance of N-atomic system in a small volume are described. The main attention we put into super-radiance photon statistics. We show the Poissonian statistics for the main part of super-radiance pulse and demonstrate the special conditions when it can be Sub-Poissonian one.

In our biophysical laboratory a new scanned probe microscope (SPM) for technical and biological application has been developed. The SPM allows to investigate sample surface by means of three different near field microscopes: scanning tunneling microscope, atomic force microscope and near field scanning optical microscope. The SPM is very rigid and can be operated in ordinary laboratory without any vibration isolation. The scanning area of the microscope is about 10 X 10 micrometers . Different technical and biological applications of the SPM are demonstrated. Results of the SPM investigations of different carbon, metal and dielectric films are described. The SPM comparison study of electrical breakdown and the conduction bistable switching effect in thin dielectric films of oxides and fluorides of some rare earth metals has been discussed. Some biological applications of the SPM viz. visualization of different bacteria (E.Coli, plague, cholera, staphylococcus), bacteria thin sections, macromolecules (plague proteins) and plague phage has been described.

The Monte Carlo methods are widely used in biooptics to calculate different characteristics of the optical radiation fields. In the most cases the radiation characteristics including local ones (fluence, absorbed dose, etc.) are calculated with non-local Monte Carlo estimates, which give the values averaged over some region. These methods can lead to large systematical errors if the characteristics have fast space variation. At the same time there are local algorithms in the theory of the Monte Carlo methods. They are widely used in calculations of fields of ionizing radiation. In particular, the famous Kalos `local estimate' allows computations of radiation flux at a fixed point. This estimate solves the problem of the systematical error but because of infinite variance it has lower convergence and stability in comparison with non-local methods. Recently a method of acceleration of convergence of the Monte Carlo estimates possessing infinite variance was suggested. In the present work this accelerated Monte Carlo algorithm is applied to the Kalos estimate under typical conditions of biooptics (rat liver irradiated by 1.064 mkm laser). It is shown that the algorithm gives the gain in computational time up to 100 times. Obtained results allow us to recommend this algorithm for calculation of local characteristics of laser radiation fields in biological tissues.

The experimental investigations of rat mesenteric lymph microvessels by using vital biomicroscopy with videotape system recorder, still pictures of frames and image processing system have been carried out. It is established that intravenous administration of sodium nitroprusside induces differently directed changes of vascular diameter. The majority of lymph vessels are dilated. Degrees of dilation in central and valve regions of lymphangions are different. He-Ne laser irradiation of mesentery at the increase of nitric oxide synthesis after sodium nitroprusside injection stimulates phasic contractions in part of the vessels. Used dose of laser irradiation doesn't influence on intact microvessels. Sodium nitroprusside increases sensitivity of lymph microvessels to He-Ne laser irradiation.

The necessary conditions have been matched to remove fluorescence of biotissues and the conditions of phantom fluorescence excitation.

We discuss coherent optical methods that hold much promise for applications in biomedicine, such as photon-correlation spectroscopy; speckle interferometry; coherent topography and tomography; diffusion wave spectroscopy; phase, confocal, and Doppler microscopy; and low-coherent interferometry and tomography.

In present paper the brief review of last years publication on laser opto-acoustics in medical applications is done. The short theory and main practical formulae are given. Several examples of practical applications of laser opto-acoustics in biomedicine such as opto-acoustic methods of layered tissues investigation and breast cancer diagnostics possibilities are shown. Some results of acoustic receivers investigation for opto-acoustic applications designed at Saratov State University are presented.

Mechanism of formation of output signal of speckle- microscope for measurements of flow of bioliquids is considered in this paper. Output characteristics of measuring system are studied. Dependence of spectral moments of output signal of speckle-microscope on velocity of bioflow and its scattering characteristics are investigated.

The theory of resonant fluorescence of multilevel system in two monochromatic intense laser fields has been applied for investigating the temporal decay of magnetic sublevels of an atom. As for two-level system the triplet of resonant fluorescence is observed, for real atom being the multilevel system the multiplet of resonant fluorescence can be observed. The excitation spectra, defining the intensities of lines in the multiplet of resonant fluorescence, and shifts of components of spectra are shown. Typical temporal dependence of fluorescence intensity for magnetic sublevels of an atom having different relaxation constants is shown. The computer simulation of resonant fluorescence for simple systems can help to understand the regularities in temporal decay curves of atherosclerotic plaque, malignant tumor compared to normal surrounding tissue.

The principal method of cataract treatment is microsurgical removal of the opaque natural lens from the eye and implantation of the artificial lens. Now offered types of the artificial lenses differ in its configuration, materials, methods of its fixation in the eye and other parameters. We performed the comparative study of the results of implantation of various types of artificial lenses in respect of visual rehabilitation of the patients. After the implantation of the artificial lens we studied the visual acuity of the patient, the post-operative refraction of the eye, and the patient complaints of visual discomfort caused by various optical effects and aberrations. Among these patient complaints we marked: reducing of the vision at the bright side light, the appearance of the light spots, halo, and chromatic coloring of the outlines of the objects, etc. The correlation between the spectral transmittance of the artificial lens and the distortion of the color perception was studied too. The surface properties of the lens material were accounted as the factor of the biocompatibility of the lens. The consideration of the artificial lens properties makes more precise the determination of the indications and contraindications for the implantation of various types of the artificial lenses.

The possibility of determination of the complicated form of the object motion by the homodyne system has been shown. The method is based on the use of Fourier representation of the function of the object motion. The results of the experimental data processing for a nonharmonic vibrating mirror have been presented.

Spontaneous cooperative emission of the pencil-shaped sample was simulated on the basis of Maxwell-Bloch equations without approximation of slowly varying (in space) amplitudes of the electric field and medium polarization. Using the numerical and derived approximate analytical solution of these equations the influence of the internal field multiple reflections (from the sample ends) on the pulse parameters was analyzed. The counter-propagating waves synchronization and pulse development acceleration are discussed.

In the present paper the polarization-transverse patterns in the multimode vector-field laser with no restriction imposed on the transverse mode number are studied numerically using the dynamical model, in which the saturation of the working transition is described analytically. We considered a unidirectional ring cavity with image rotation. The active medium of the laser is assumed to be homogeneously broadened. The Zeeman splitting of the active transition controlled by the axial magnetic field was taken into account. The medium polarization and levels population is assumed to be adiabatically eliminated (class-A laser). The vector-field catastrophes were used for the description of pattern dynamics.

General properties of the dynamical model describing the propagation of a misaligned astigmatic twisted Gaussian beam in axially symmetric nonlinear waveguides are studied. Nontrivial dynamical regimes are revealed in different types of waveguide media including those with dissipation and possible applications are discussed.

Propagation of radiation in non-regular single mode fibers is investigated. Fibers with the core diameter step and tapers are taken into consideration, as well as cylindrical fibers with the Kerr-like nonlinearity of the fiber material. Paraxial wave equation is solved numerically by the sweep method. Power flow and spot size of the field propagating along the fiber axis is calculated. Accuracy of the numerical technique is analyzed relative to the different fiber structures.

The mapping for normalized peak amplitude of a pulse in the all-fiber ring laser is derived. The results of numerical simulations of pulse-train dynamics are presented. The regimes of double-periodic pulse-train, absence of oscillations and the hysteresis are found.

A new coherent laser multi-pulse technique is proposed to measure the population of the individual metastable state of antiprotonic helium `atomcules' and to control the decay kinetics in the adjacent transition chains. In particular, the method allows one to check up the mechanisms of quenching of high-energy states.

The effect of external signals of different shapes (constant, serrated and others) on the ring neural network modeling the visual perception is investigated numerically. New specific features in the dynamics of the neural network, such as the excitation, the swapping and the depression, were observed. The cooperative amplication of the external signal and the memory effect have been observed.

Phenomenological description of the local polarization structure of multiple scattered speckle patterns is discussed. Different approaches to these structures characterization are reviewed. Experimental results obtained with multiple scattering model objects show that statistical properties of local polarization parameters can be described by using the `quasi-scalar' approach; in this case multiple scattered speckle pattern is interpreted as the superposition of two orthogonally polarized fully developed statistically independent components.

The investigations of optical spectra at various treatments of NaCl-Ni crystals were made. It is determined that variations of the spectra may not be explained by creation of nickel clusters only. A possible reason of spectra behavior was offered.

The goal of the submitted work is to study of structure of luminescent clusters in alkali halide crystals by XEOL method. The results are presented for KBr single crystals using excitation spectra of optical luminescence. Excitation of the luminescence executed by X-ray in the BrK edge energy region.

Deviation of output characteristics of Doppler system for blood microcirculation measurements have been investigated. Dependence of form of Doppler spectrum on the number of speckles, integrating by aperture, has been studied in experiments in vivo.

Low power laser Doppler system with high-sensitivity photodetector is developed for in vivo investigations. The level of power of incident laser radiation corresponds to the requirements of eye safety. Results of in vivo experiments with a model of blood vessel are presented.

Experimental in vitro studies of speckle-modulated laser field arising after transmission through different type of human cataracties lenses are presented. Computer analysis of digital imaging has allowed to determinate the degree of destruction of spatial coherence scattered laser beam and the angle of resolution of the retina using Retinal Analyzer of Vision in diagnosis of cataract. Comparison with clinical investigation in vivo has been made.

The method of calculation of the diffracted acoustic field amplitude distribution by Fourier transform for the round emitter in approximation of isotropic medium has been described. The numeric results in form of dependencies of the relative acoustic field amplitude on the dimensionless coordinates have been presented at four examples of acoustic heads.

Monte Carlo method has been used to simulate the effects of light focusing in highly scattering tissues, such as dermis. Spatial distributions of light both for ideal focusing systems and for systems with aberrations have been investigated.

Recently noninvasive near-infrared techniques have been developed to determine the concentrations of oxygenated and deoxygenated haemoglobin in the living biological tissue. New dual wavelength and dual frequency instrument with the phase modulation of the laser light has been designed and built for studies the oxygen dynamics in human tissue. This instrumentation is low cost and acquire data in widely different frequency and wavelength regions. We have presented the comprehensive calibration procedures applied to the instrument and demonstrated the appropriate working range of the measuring optical parameters. Also has been calculated the haemoglobin saturation of the tissue-like phantom using the results of the photon-diffusion theory for infinitive geometry approximation. Our results have shown the good accuracy and sensitivity in the different experimental conditions suitable for clinic researches.

Concurrently the measurement of autocorrelation function of the light backscattering from the forearm and phase and amplitude changes of the phase modulated photon diffusion wave has been acquired in the arm cuff experiment. Dynamical performances with the varying blood pressure are presented and analyzed.

The dependence of intensity distribution of diffusely reflected light during medium irradiation with narrow laser beam on optical parameters of multiple scattering media such as tissue has been investigated. The dependence of backscattered spot size on penetration depth as well as dependence of sensitivity on absorption and scattering coefficients have been analyzed by Monte Carlo simulation. Experiments in model multiple scattering media which determine the dependence between the spot size of backscattered radiation and optical characteristics have been carried out. Scanning with optical fibers have been used for measurements of intensity distribution.

Results of simulations of Doppler spectra at the scattering of laser radiation from for tissue, containing a single thin blood vessel, are presented. The form of intensity fluctuation spectra has been analyzed. Doppler shift of the frequency of incident laser light has been investigated as a function of laser beam radius, blood vessel radius and vessel position.

The dependence of reflectance on the scattering coefficient value and the distance between the emitting and receiving fibers are analyzed using Monte Carlo simulation technique. The preliminary results of in vivo measurements of the reflectance at 830 nm of the human skin immersed by various oils and lotions are described.

In this paper, we described of methods of noninvasive study of the human brain. This overview includes description of optical properties of cerebral tissue, technical characteristics of noninvasive techniques of the human brain examination, such as temporal and spatial resolution, optimal optical parameter for optical imaging, etc. We also touch upon a subject of visual simulation in the optical imaging of the human brain and correlation of brain electrical activity and optical imaging.

The Monte-Carlo method was used to study the effect of multiple light scattering on the medium's polarization characteristics. The influence of the scattering system parameters and experimental conditions on the results of LSM measurements were estimated. Calculation was performed for a monodisperse system of spherical particle. The scattering medium was enclosed in a spherical and a cylinder cells. The influence of cell wall thickness and light reflection at the medium-glass and glass-air interfaces was regarded. Various parameters of incident beam, cell diameter and scattering particles dimensions were employed for calculations.

The device, offered for reviewing, was designed and developed for photodynamic therapy of oral cavity mucous diseases and for laboratory experiments on the red light influence on the bacterial colonies in presence of a dye. The device has rather simple construction, it is cheap but convenience in use.

This paper is concerned the problem of calculating the polarization and spatial characteristics of laser radiation scattered by the eye lens. In calculations, a complete general solution of the problem of interactive electromagnetic scattering by clusters of arbitrary configured nonidentical spheres was used. The light scattering matrix, the image of a speckle structure of scattered radiation, the intensity distribution are received. The optical constants and dimensions of the particles were varied in a range of values corresponding to the normal and pathological lens. The modeling results are compared with the previously reported experimental indicatrixes of the eye lens.

Optical model of a human tooth enamel surface and results of numerical calculations of a coherent gaussian beam scattering on enamel surface are represented. The experimental set-up for complex investigations of optical properties of hard tooth tissues is described and tested.

In this study we investigate the potentials of imaging the morphological and physiological features of cells by means of Laser Phase Microscopy (LPM). Since LPM is a relatively new microscopical device it has only been used in a few experimental laboratories so far. Human carcinoma cells were treated with the chemical stress factor ethanol and the patterns of the phase shift distributions were observed for single cells.

Experimental study and computer simulation were used to analyze tissue optics during a process of optical clearing due to refractive index matching. Tissue samples of the human and bovine sclera and the collagen sponge as a phantom were investigated. Osmotically active solutions, such as verografin and propylene glycol, were used as chemicals. A characteristic time response of human scleral optical clearing in the range 1 to 20 min was determined. The matter diffusion coefficient for the scleral samples to impregnated by verografin solution were experimentally estimated; the average value is 1.27 (DOT) 10^-5 +/- 3.77 (DOT) 10^-6 cm²/sec. The results are general and can be used to describe many other fibrous tissues.

The very rapid development of optical technology has followed a pattern similar to that of nuclear magnetic resonance: first, spectroscopy and then imaging. The accomplishments in spectroscopy have been significant--among them, early detection of hematomas and quantitative oximetry (assuming that time and frequency domain instruments are used). Imaging has progressed somewhat later. The first images were obtained in Japan and USA a few years ago, particularly of parietal stimulation of the human brain. Since then, rapid applications to breast and limb, together with higher resolution of the brain now make NIR imaging of functional activation and tumor detection readily available, reliable and affordable devices. The lecture has to do with the applications of imaging to these three areas, particularly to prefrontal imaging of cognitive function, of breast tumor detection, and of localized muscle activation in exercise. The imaging resolution achievable in functional activation appears to be FWHM of 4 mm. The time required for an image is a few seconds or even much less. Breast image detection at 50 microsecond(s) ec/pixel results in images obtainable in a few seconds or shorter times (bandwidths of the kHz are available). Finally, imaging of the body organs is under study in this laboratory, particularly in the in utero fetus. It appears that the photon migration theory now leads to the development of a wide number of images for human subject tissue spectroscopy and imaging.

Various light scattering and optical techniques have been investigated as potential candidates for characterization of multiphase polymeric materials. The Mueller matrix formalism is briefly mentioned as an effective procedure of complete optical description of the medium. The effects of multiple and dependent scattering as well as coherent and diffuse light attenuation are discussed in model calculations and corresponding experiments (small-angle light scattering, time-resolved light scattering, transmission or diffuse reflectance measurements and image analysis). The following physical processes has been investigated: kinetics of phase separation and dissolution (demixing) of polymer blends, stress whitening process and photon migration in polymer composites. Light scattering and the diffuse reflectance method were used to characterize heterogeneous structures of polypropylene-based materials before and after solid-state deformation. The application of a hybrid model of Monte Carlo simulation and diffusion theory recently developed to describe propagation of photons into sufficient depth in the turbid media is presented for polypropylene samples with various amounts of ethylene-propylene rubber particles. The value of reduced scattering coefficient determined from experiment is an important structural parameter with direct relationship to size of particles and their volume fraction in the polymer matrix. Since speckles play an important role in many physical phenomena, it is essential to fully understand their properties. Structural aspects of the laser speckle techniques and their application in polymer physics are presented.

Speckle arises as a natural consequent of the limited spatial-frequency bandwidth of the interference signals measured in optical coherence tomography (OCT). In images of highly scattering biological tissues, speckle has a dual role as a source of noise and as a carrier of information about tissue microstructure. The first half of this paper provides an overview of the origin, statistical properties, and classification of speckle in OCT. The concepts of signal-carrying and signal-degrading speckle are defined in terms of the phase and amplitude disturbances of the sample beam. In the remaining half of the paper, four speckle- reduction methods--polarization diversity, spatial compounding, frequency compounding and digital signal processing--are discussed and the potential effectiveness of each method is analyzed briefly with the aid of examples. Finally, remaining problems that merit further research are suggested.

Most of the objects to be found in nature are essentially random, i.e. affecting the probing optical radiation they transform its amplitude and phase parameters in complex, hardly predicted manner. Traditionally, such objects are described in the framework of the theory of probability and mathematical statistics. In last decade, however, the novel approach is outlined according to which rather extensive class of natural and artificial objects can be represented as any mixture of deterministic and random spatial structures. The fractals, i.e. the objects possessing the feature of structural self-similarity in the strict or in any generalized sense, are the most adequate model describing such objects'. Interaction of these objects with a coherent radiation results in stochastic spatial structures. Here we consider some techniques Lor structural diagnostics of an object that are based both on the probabiitic approach 'and on the stochastic one. Speaking about random optical fields, we will imply spatially inhomogeneous stationary fields resulted from interaction of coherent radiation with random phase or amplitude objects. One encounters such a speckle field solving the problem of remote structural diagnostics of an object. Besides, we will limit our consideration with the scalar approximation. Surface roughness is often considered as the classic model of the object causing spatial modulation of the probing beam. On the one hand, it is easily to prepare such an object with the independently controlled parameters. On the other hand, the diagnostical problem is of the most practical importance for the objects of this kind. That is why, we will illustrate the capabilities of the optical correlometric techniques using a rough surface as the basic model, as a rule. At the same time, amplitude and phase deterministic or quasi-deterministic objects will be also under our consideration, and the fractals whose main feature consists in their structural self-similarity' will be the most significant examples of these objects. It is well known, that genera! solution of a statistical diagnostica! problem consists in reconstruction of the height distribution function for a rough surface inhomogeneities or, alternatively, in finding out the complete set of the statistical moments characterizing the object's structure. If the object is assumed to be random in the strict sense, then its description in terms of a height distribution function or in terms of a complete set of the statiical moments represents comprehensive solution of the rtatistica! diagnostical problem. In practice, however, necessity in such a general statistical description occurs to be rather rare. In accordance with the well known statements of mathematical statistics, knowing of several low-order statistical moments is enough for characterization of the object under study in its significant features and in desirable approximation. In the case of rough surfaces, the correlation length and root-mean-square (rms) of roughness from the mean surface line (that is linked by simple relation with a phase variance of the boundary field in some practically important cases) are the main statistical parameters adopted for rough surface characterization. As any simple model for surface roughness is used, particularly, by presuming Gaussian or another symmetrical height distribution function, the diagnostical problem is solved in principle by determining these parameters through any of the known high efficient techniques2. For all that, the question arises: if the experimentally found parameters are corresponding with desirable accuracy to the intrinsic roughness parameters? In other words, the problem of adequacy of the used model for a rough surface arises. It is stated in some recently reported studies that the fractal model occurs to be adequate for rough surface characterization in numerous practical applications23. So, particularly, for a machined surface finish such a conclusion is grounded in Ref.2 . It is not less important, attraction of the approaches of a chaos theory as well as fractal optics methodology enables to extend the circle of the problems of rough surface diagnostics that can be solved in the framework of the unified approach, irrespective of the phase variance at the boundary field. Of course, in the framework of this approach, the solution of a diagnostical problem is formulated in unconventional terms, such as chaos dimension closely related to the notion of entropy. The diagnostically important interconnection among the dimension parameters of the scattered optical radiation and the corresponding dimension parameters of the object's structure is found. Somewhat (to say, in the mentioned above surface finish problem) unambiguous interconnections occur to be put in evidence among these (dimensional) parameters with the traditional ones, such as the standard deviation of the surface profile from the mean surface line and the correlation length of surface inhomogeneities2. This paper is devoted to consideration of the present state of the problem briefly outlined above and interrelations among different mentioned approaches.

An introduction into the elements of diffraction theory of coherent scattering of vector waves for size and velocity measurements is proposed to discuss. In traditional approach, a square-law detector is to observe beating in optical signal consists of two components: scattered and not-scattered scalar waves. The basis of proposed metrology is beating of two scattered coherent vector waves with variable states of their vectors of polarization (Coherent Light Beating Scattering (CLBS)) on a photodetector. Vectorial optical signal of CLBS is considered in framework of Fraunhofer diffraction of two plane vector waves by a single particle in case of periodical modulation of vector of polarization described as Jones vector. The formalism of Jones matrix is proposed to describe CLBS by a distribution of particles to control their sizes and velocities. A portable CLBS-spectrometer for size and motility application in biology is described. In traditional spectroscopy of optical beating, a particle alone provides with one scattered component of scalar wave to mix with a narrow-band reference wave on a square-law photodetector. As a result, a community of particles in motion gives fluctuation of intensity available for next spectral analysis of electrical signal. On the contrast, by CLBS, a single particle is to form two vectorial scattered coherent components to beat on a photodetector that joints beating and scattering as the basis for the new active control of a distribution of particles with the principal possibility of simultaneous k- spectroscopy of sizes and (omega) -spectroscopy of velocities. The CLBS-spectrum of alive Dunaliella is presented as a first example to develop a new optical standard to measure bioactivity.

We use heterodyne detection to characterize the Wigner phase space distribution W(x,p) of an optical field in position x and momentum p. This method yields smoothed Wigner phase space distributions directly as contour plots and can be applied with either coherent or low coherence light sources. The measured phase space distributions are used to characterize the light sources and to study light propagation in multiple scattering media. These techniques may find important applications in understanding and enhancing images obtained in coherence tomography.

Laser speckle strain measurements in biological tissues and some synthetic biomaterials, such as translucent dental composites and ceramics, are often complicated by the physical properties of the materials. For example, speckles generated by illuminating soft biological tissue with laser light are subject to rapid decorrelation due to the Brownian movement of water and scattering particles in the tissues and to cellular motions. In addition, the penetration of the laser beam into the tissue or translucent biomaterial results in multiple scattering and a complete depolarization of the speckle field. This may complicate the evaluation of the strain field when a force is applied to the material because the speckle pattern shift is providing information from the surface of the material as well as from the bulk sample, where the strains may or may not be the same as on the surface. This paper presents a variation of a speckle processing scheme originally called the `Transform Method' for evaluating both surface and bulk strain rates and total strains in biological tissues and translucent biomaterials. The method is not a correlation-based technique, but instead relies upon 2D frequency transforms of time series of 1D speckle pattern records stacked into 2D arrays. The method is insensitive to speckle field depolarization and, compared to correlation-based techniques, is relatively insensitive to speckle decorrelation. Strain rates and total in-plane strains were measured in both hard (cortical bone) and soft (artery segments) biological tissues and in translucent biomaterials (dental ceramics). Potential applications to medical diagnostics and biomaterials science are also discussed.

A highly portable, fast, safe and affordable imaging system that provides interpretable images of brain function in full- and pre-term neonates within a few seconds has been applied to neonates with normal and pathological states. We have used a uniquely sensitive optical tomography system, termed phased array, which has revealed significant functional responses, particularly to parietal stimulation in neonate brain. This system can indicate the blood concentration and oxygenation change during the parietal brain activation in full- and pre-term neonates. The preliminary clinical results, especially a longitudinal study of a cardiac arrest neonate, suggest a variety of future applications.

To evaluate transscleral glaucoma surgery techniques using ultrashort pulsed lasers, we attempted to produce photodisruption on the inner surface of the sclera without damaging the overlying tissue. We identified two methods, using pulses centered at 1700 nm and a transparency inducing drug, to produce the spatial and temporal confinement of the pulse necessary to produce photodisruption in the highly scattering sclera. When fully developed these concepts may help address the longstanding limitations of current glaucoma surgical techniques.

We investigated the spatial confinement of laser beams focused through human cornea and sclera using long near infrared wavelengths. Using a 0.4 numerical aperture lens, we measured the spatial transmission of the smallest emergent beam on the back surface of the tissue. We found that standard axial transmission measurements over estimate the amount of unscattered light for the sclera and that 1600 nm to 1700 nm had the maximum unscattered transmission through cornea and sclera. The light confinement may be useful in producing localized subsurface linear and nonlinear optical processes.

The near-infrared spectroscopy technique is being used for non-invasive in vivo measurements and quantifying of oxygenation of hemoglobin in the skin microcirculation. The method utilizes a simple model for studying of skin oxygenation. The aim of this lecture is to show young researches and students some perspectives of near-infrared spectroscopy as a technique with great promise and a new medical tool for non-invasive diagnostics and monitoring of blood oxygenation in vivo.

Imaging characteristics of photon diffusion imaging in highly scattering media such as human tissues was illustrated with the concept of transfer function by means of Fourier analysis. The illumination photon source, and the optical properties of the sample are cascaded to construct a whole system. As an information transfer channel, the imaging system takes the role of a low pass filter. Low frequency components are measured with a photon diffusion imaging system.

We detected oxyhemoglobin (HbO₂) content change and blood volume of the bleeding model in vivo with NIRS imager. The results showed that the minimum detect limit of NIRS imager is 0.5 ml and the optimum detect depth is 2 - 5 cm under skin. In our test, the imager could detect small change of the blood volume easily, but the HbO₂ content in hyperemia location hadn't obvious change. The results suggested that injected blood was venous blood which had lower HbO₂ content level. In single channel blood oxygen test, we observed that deoxyhemoglobin, blood volume had significant changes after 0.5 ml venous blood was injected each time. But the oxyhemoglobin hadn't obvious change too. The NIRS imager could determine the location, range and depth of ischemia or bleeding diseases. Because the instrument is cheap, portable, and operate easily, it is promising in family diagnosis and sport medicine.

A NIRS imager is used as a real time monitor in psychological test to record the response in blood oxyhemoglobin state and blood flow of the frontal gyri of human subject. The imager has 9 lamps and 4 dual detector pairs and an area of 9*4 cm. In mental work and pattern recognition test, we recorded oxygen consumption and blood flow changes of the volunteer's frontal gyri. The psychological results showed that down part of the left frontal gyri has intensive relation with pattern recognition and has definite boundaries. However, the mental work involved more zones of frontal gyri and it may be a more complicated think model. The results also suggested that brain have an exquisite and complicated adjust ability. As a result, the oxygen supplement in excited area increased as the neuron excited.

To measure low frequency small displacement vibration, we develop a non-contact sensor based on the optical feedback effect in a laser diode. The principle and experiment setup are described. Experimental results show that the sensor is sensitive to vibration in the micrometer range.

We propose photon-density-wave fluctuation correlation spectroscopy as a method to study the dynamics of tissue optical properties. Phantom measurements have shown that our frequency-domain instrument is appropriate to explore intensity, modulation and phase fluctuations in the frequency band from 0 to 125 Hz. Preliminary in vivo studies have revealed a rich optical dynamics in human tissues.

Measurement of optical properties during coagulation can be used for monitoring of the extent of thermal injury in real time. Knowing optical properties of native and coagulated tissues one can optimize treatment parameters and provide precise coagulation of malignant and benign lesions. Attenuation coefficient and total diffuse reflectance of native and coagulated canine liver were measured with the use of optoacoustic and diffuse reflectance techniques. Absorption and reduced scattering coefficients were calculated using the obtained data. Total diffuse reflectance, absorption, reduced scattering, and attenuation coefficients of canine liver increase due to protein coagulation. The capability of optoacoustic technique to detect directly changes in attenuation coefficient can be used for monitoring of tissue coagulation in real time.

We describe the results of the study of light propagation and scattering in a model biological tissue comprising moving particles simulating blood perfusion. The study was performed by means of Monte Carlo simulation. The obtained dependencies of the total intensity and of the Doppler spectra of the backscattered light on the model parameters are analyzed. The CW and ultra-short pulse modes of sample probing and time gating of the detected signal are considered.

Our research project is focused on theoretical and experimental studies into the possibility of in vivo monitoring of blood glucose concentration. Previous experiments demonstrated that the presence of glucose dissolved in aqueous solution of polystyrene microspheres increases the refractive index of this solution due to glucose hydrophilic properties. As a strong osmolyte glucose influences the scattering properties of any particles or fibers suspended in water or biological fluids. We measured profiles of absorbed laser energy distributions as a function of glucose concentration in aqueous solution of polystyrene microspheres colored with potassium chromate. Experiments were performed at the wavelength of the Nd:YAG laser third harmonic, (lambda) equals 355 nm. The results obtained demonstrated a 4.5% decrease in effective optical attenuation coefficient with a 100 mM increase in glucose concentration. These initial results demonstrated that the effect of glucose on optical attenuation of turbid aqueous solutions is small but reliably measurable with the use of the time-resolved optoacoustic technique.

The mathematical model of processes in UV-irradiated furocoumarin-sensitized epidermis is presented taking into account the mutual influence of keratinocytes and melanocytes populations. The model describes epidermis as a hierarchical structure on tissue (keratinocytes-melanocytes cooperation, melanin screen formation), cellular (proliferation and differentiation, transitions between subpopulations), subcellular (cell movement on mitotic cycle, generation, maturing and migration of melanosomes), and molecular (melanin synthesis, processes of DNA damage and repair, molecular signal transduction) levels.

In this work, as a part of complex work aimed at the development of tissue-like phantoms of biotissue and evaluation of their fluorescence properties, we obtained fluorescence spectra (over 480 - 670 nm interval) of the phantoms and their components under 405 +/- 20 nm excitation. Fluorescence escape from the layer modeling collagenous stroma with capillary network, as dependent on blood content in it, was studied. It was shown that collagen added to upper layers of phantom causes an uniform increase of intensity over whole spectral range under study, whereas the addition of NADH to `epithelium' results in the increase in 480 - 580 nm interval only.