This PDF file contains the front matter associated with SPIE Proceedings Volume 8699, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Fundamental understanding of the light-matter interaction in the context of nano-particles is immensely benefited by the study of geometry dependent tunable Localized Surface Plasmon Resonance (LSPR) and has been demonstrated to have potential applications in various areas of science. The polarization characteristics of LSPR in addition to spectroscopic tuning can be suitably exploited in such systems as contrast enhancement mechanisms and control parameters. Such polarization characteristics like diattenuation and retardance have been studied here using a novel combination of Muller-matrix polarimetry with the T-matrix matrix approach for silver nano-rods to show unprecedented control and sensitivity to local refractive index variations. The study carried out over various aspect ratios for a constant equal volume sphere radius shows the presence of longitudinal (dipolar and quadrupolar) and transverse (dipolar) resonances; arising due to differential contribution of polarizabilities in two directions. The overlap regions of these resonances and the resonances themselves exhibit enhanced retardance and diattenuation respectively. The spectral and amplitude tunability of these polarimetric parameters through the aspect ratios to span from the minimum to maximum ([0, 1] in the case of diattenuation and [0, π] in the case of retardance) presents a novel result that could be used to tailor systems for study of biological media. On the other hand, the high sensitivity of diattenuation dip (caused by equal contribution of polarizabilities) could be possibly used for medium characterization and bio-sensing or bio imaging studies.

The electrocardiography (ECG) signal is often used as a reference signal when calculating pulse transit times (PTT) measured by photoplethysmographic (PPG) sensors. In addition, ECG measurements are widely used in clinical health monitoring. In clinical measurements, small changes in the time delays of R waves in relation to blood flow pulsations between each ECG measurement are not relevant. In most cases, they would not even be observed, due to the rather low sampling rates used in clinical ECG devices. However, in PTT measurements, where time delays are measured with an accuracy of milliseconds, the placement of ECG electrodes can have a distinct effect on the results.

This paper presents case studies of ECG signals measured simultaneously and independently by two ECG devices. We explore what effect different placements of ECG electrodes have on the R wave of the QRS complex and how it should be taken into account when used as a reference signal in pulse transit time measurements of blood flow. Additionally, we study what kind of ECG electrode placements are most suitable for PTT measurements.

In the conventional cross-correlation approach to reconstruction of displacements (and then the strain field), the reduction of correlation between the consequently obtained images caused by distortions of scatterer patterns in deformed tissues is a negative factor reducing the accuracy of the displacement-field reconstruction. However, just this reduction in the cross-correlation between the images of deformed tissues can be intentionally used for evaluation of the tissue rigidity. Evidently, in areas with higher rigidity the distortions of the scatterer pattern in deformed tissues are smaller and, correspondingly, the reduction in the cross-correlation between the consequent OCT images is also smaller. Observation of such a cross-correlation field we call the correlation-stability approach (CS-approach) to mapping the relative rigidity of biological tissues. The proposed CS-approach is illustrated by numerical simulations corresponding to two characteristic cases (sheared or compressed samples with average strain range 25 - 100 %). This strain level is favorable for performing such mapping "by hand" and in vivo conditions. Some examples of such in vivo obtained relative-rigidity images are presented in this report.

Speckle pattern texture analysis method is applied to measure surface roughness of human skin. The method is based on analyzing of a gray level co-occurrence matrix occurred from a speckle image of a rough surface. Paper with different surface roughness is used as a skin phantom. The roughness is controlled by profilometry measurements. The developed methodology could find wide application in dermatology and tissue diagnostics.

Statistical properties of laser speckles, formed in skin and mucous of colon have been analyzed and compared. It has been demonstrated that first and second order statistics of “skin” speckles and “mucous” speckles are quite different. It is shown that speckles, formed in mucous, are not Gaussian one. Layered structure of colon mucous causes formation of speckled biospeckles. First- and second- order statistics of speckled speckles have been reviewed in this paper. Statistical properties of Fresnel and Fraunhofer doubly scattered and cascade speckles are described. Non-gaussian statistics of biospeckles may lead to high localization of intensity of coherent light in human tissue during the laser surgery. Way of suppression of highly localized non-gaussian speckles is suggested.

An original methodology is developed for scanning of the arterial intima morphology using the atomic force microscopy. The probing nanolaboratory NTEGRASpectra (NT-MDT, Russia) was itilized. The pictures of the coronary artery intima topology were obtained with the resolution of 1 nm. The 3D model of the ‘endothelial cell surface - low density lipoprotein (LDL)’ complex was constructed. Using the ANSYS software, the deformation of LDL particle was found as well as the stress distribution at the moment of the macromolecule and endothelial surface collision. The largest normal and tangential stresses are found in the area of LDL interaction with the surface. These stresses are 2.173 and 0.053 kPa, respectively. It was shown that the LDL structure is being highly strained, which leads to the molecule compression and crease. Therefore, one can conclude that at the moment of LDL entering the intercellular hiatus the macromolecule will be suffering the overall deformations and large modification of its structure.

In present study we developed the new method of colour visualization of red blood cells without using any chemical staining. The method based on physical phenomena a white light interference on thin transparent films. It is shown that in the case of thin human blood smears colour interference contrast occurs on solid polished substrates. The best contrast shows substrates with maximal refractive index (Mo, W, Si). These materials have been selected as substrate instead of ordinary microscopic slide in reflected light microscopy. It is shown that reflection of incident white light from blood cell surface and boundary cell-substrate generate two coherent lights. The second one (object signal) after passing through red blood cell gathers additional phase and after interference interaction with reference signal (light reflected from outer cell surface) enables cell image in colour. Number of blood smears of healthy persons (control) and patients who were diagnosed with cancer are presented. It is concluded that the offered method may be used as an effective diagnostic tool to detect early stage blood cells lesion by its interference painting in white light. Offered method may be used in research laboratories, hospitals, diagnostic centres, emergency medicine and other as complementary diagnostic tool to present convenient optical and electron microscopy technique.

We present a peer-to-peer realization of the online object oriented Monte Carlo code as a further development of the unified model of photon migration in complex turbid media such as biological tissues. The object oriented programming is used for to generalization of the code for multi-purpose use in various applications of biomedical optics. The peer-topeer network share their GPUs communicate and technique utilizes parallel computing on Graphical Processing Units for acceleration and a web application solution to provide users with the direct access for on-line modeling. We demonstrate that Peer-to-Peer realization could potentially deal with the limitations imposed by the multi-user access to the on-line modeling. Currently the online MC tool is available to the biophotonics community through its website hosted in Australasia: www.biophotonics.ac.nz

To determine the differences between the optical clearing effects created by ethylene glycol in fresh and frozen samples, we have performed several measurements from samples in both conditions. Fresh samples were used after animal sacrifice and frozen samples were kept at -20°C for 72 hours. The different measurements performed with samples from both cases were total transmittance, collimated transmittance, total reflectance and specular reflectance. Considering, for instance, collimated transmittance measurements, we have verified that the spectra measured from both samples before adding the solution present different levels of collimated transmittance. The time-dependence evolution of the collimated transmittance spectrum is similar between both cases of samples, but since they present different levels of “natural” transmittance, the optical clearing effect is observed at different levels if we compare between fresh and frozen samples.

We are proposing a new method for enhancement of optical clearing agent delivery into the skin using fractional laser microablation of the skin surface. The Palomar Lux2940 erbium laser with the wavelength 2940 nm and pulse duration of 5 ms was used as a light source. Two regimes of laser action were used in the experiments: the first one realized microablation of skin upper layer and the second one created microchannels in skin. As optical clearing agents mineral oil and PEG-300 were used. In vivo studies were carried out with white outbred rats. Both parameters: the permeability coefficient of the agents in the tissue and the optical probing depth were measured using the OCT system at a wavelength of 930 nm. The following values of the permeability coefficient of the skin with microablation were obtained: (3.41±0.46)×10^-5 cm/s and (2.35±0.30)×10^-5 cm/s for mineral oil and PEG-300, respectively, at the use of the surface microablation and (3.32±0.09)×10^-5 cm/s and (3.61±0.34)×10^-5 cm/s for mineral oil and PEG-300, respectively, at the use of the microporation. The results have shown that the joint application of mineral oil with microablation in the first regime promotes maximal (nearly 2-folds) increasing of optical probing depth in 30 min. Obtained data can be used for development of optical diagnostic methods of skin diseases.

The changes in optical transmittance of human adipose cell layers sensitized by indocyanine green (ICG) as a result of photodynamic action were found and studied. It was revealed experimentally that due to the selective action of laser radiation on fat tissue sensitized by ICG the spatial distribution of its optical transmittance becomes more homogeneous. The statistical computer processing of digital images allowed one to estimate tissue optical transmittance, its spatial and temporal distributions. These quantitative estimations correlated well with the visible changes of tissue images. The measurements carried out gave an opportunity to suggest the interpretation of the phenomenon observed.

Multi-resolution analysis on the spatial refractive index inhomogeneities in the connective tissue regions of human cervix reveals clear signature of multifractality. We have thus developed an inverse analysis strategy for extraction and quantification of the multifractality of spatial refractive index fluctuations from the recorded light scattering signal. The method is based on Fourier domain pre-processing of light scattering data using Born approximation, and its subsequent analysis through Multifractal Detrended Fluctuation Analysis model. The method has been validated on several mono- and multi-fractal scattering objects whose self-similar properties are user controlled and known a-priori. Following successful validation, this approach has initially been explored for differentiating between different grades of precancerous human cervical tissues.

We developed a system for the analysis of the spatial distribution of photosensitizers (PS) based on tetrapyrrole compounds in the tissues of the retina. Tetrapyrrole compounds were chosen because the most of them are characterized by strong absorption in the tissue transparency window. Calibration curves for determining the concentration of PS by different methods were constructed. Registration system of PS’s fluorescence consists of two optical channels. First channel based on single point spectroscopic technique is used to determine exact concentration of PS at a certain point of the field. Second channel based on imaging sensor is used for concentration mapping in whole field of view. The joint use of these two methods allows determining the concentration of PS in different points of the field quickly and accurately, which provides the exact determination of tissues in pathologic condition and informed choice of irradiation dose for photodynamic therapy.

It is of considerable current interest to develop various methods which help to understand and quantify the cellular association in growing bacterial colonies and is also important in terms of detection and identification of a bacterial species. A novel approach is used here to probe the morphological structural changes occurring during the growth of the bacterial colony of Bacillus thuringiensis under different environmental conditions (in normal nutrient agar, in presence of glucose - acting as additional nutrient and additional 3mM arsenate as additional toxic material). This approach combines the quantitative Mueller matrix polarimetry to extract intrinsic polarization properties and inverse analysis of the polarization preserving part of the light scattering spectra to determine the fractal parameter H (Hurst exponent) using Born approximation. Interesting differences are observed in the intrinsic polarization parameters and also in the Hurst exponent, which is a measurement of the fractality of a pattern formed by bacteria while growing as a colony. These findings are further confirmed with optical microscopic studies of the same sample and the results indicate a very strong and distinct dependence on the environmental conditions during growth, which can be exploited to quantify different bacterial species and their growth patterns.

Methods of s-LASCA and t-LASCA have been adopted to problem of monitoring growth of colonies of bacteria E. coli culture B6. Set-up of LASCA-microscope is developed. Results of experimental investigations of influence of speckled biospeckles on results of monitoring of growth of bacterial colonies have been obtained.

Laboratory experiments conducted in Saratov State University in the first half of 2012 revealed crystal formations on the surface of etched dentine after it had been exposed to 95% ethanol in solution for 30 days at room temperature. It was discovered that the structures observed were calcium-phosphate crystals. The nature of crystal formation on rough dentine surface was described based on substance diffusion in solution, which resulted in dentine becoming spatially inhomogeneous over time. The crystal formation was established to be determined by the limited ion redistribution in dentine material.

Crystal formations were observed on the surface of etched dentine after it had been exposed to 95% ethanol in solution for 30 days at room temperature. 3D visualization of surface formations was carried out using a scanning electron microscope and Alicona 3D MeX software (Alicona GmbH). Metric characteristics of the mentioned above structures were evaluated and the nature of possible errors on the steps of model design was studied. It was shown that the shape of crystal models were likely to be approximated by ellipsoid segments.

The characteristic sizes of elementary crystallites in the composition of dentine substrate with calciumphosphate crystal formations on its surface have been studied using x-ray diffraction (XRD) analysis for phase identification. Most probable mechanisms explaining changes in elementary crystallite sizes in the process of crystal formation were discussed.

It is important to identify patients with chronic obstructive pulmonary disease (COPD) and lung cancer in the early stages of the disease. The method of laser opto-acoustic gas analysis, in this case, can act as a promising tool for diagnostics.

The material for this study were the gas emission samples collected from patients and healthy volunteers – samples of exhaled air, swabs from teeth and cheeks. A set of material was formed three groups: healthy volunteers, patients with COPD, lung cancer patients.

The resulting samples were analyzed by means of laser opto-acoustic gas analyzers: with intracavity location detector (ILPA-1), with extracavity location detector (LGA-2). Presentation of the results in an easy to visual form was performed using the method of elastic maps, based on the principal component analysis.

The results of analysis show potentialities of usage of laser optoacoustic spectroscopy application to assess the status of patients with chronic obstructive pulmonary disease and lung cancer.

This work describes availability of immobilization of monomers and dimers of erythrosine into collagenase molecules. By means of the spectral investigations it was obtained that emission of the dye dimers dissolved in collagenase solution is. Erythrosine dimers don't fluoresce in water and buffer solutions; however its fluorescence can be seen if complexes of monomer-ferment and dimers-ferment were formed.

Investigation of a dependence of a registered signal on an extinction parameter μ of a scattering media (the water solution of milk, thickness L) at an acoustooptic tomography showed the signal values could be essentially differed at the same μL in various charges of milk. It was essentially noticeable at the medium parameter μL <18. In the present work the influence of medium scattering anisotropy parameter g on the registered signal value S was experimentally studied. As the scattering media the water solutions of the mixtures of a skimmed milk and cream in some proportions were used. The result of the study is the necessity to take into consideration the possible g-factor change in the scattering media including biological ones at a decision of the acoustooptic tomography inverse problem.

The isolated and combined effect of heliogeophysical factors and low intensive electromagnetic radiation of millimeter diapason at the metachromasia reaction of the yeast Saccharomyces cerevisiae was studied. It was established that longterm influence of EMR 65 GHz induced changes in the response of cells towards heliogeomagnetic disturbance. On our opinion millimeter waves may reduce the effect of heliogeophysical factors on living organisms because of destabilization of the intracellular water structure.

Near infrared laser immunotherapy becomes now a new promising research field to cure the patients with cancers. One of the critical limitation in medical application of this treatment is availability of the specific markers for delivery of laser-sensitive nanoparticles. When coupled to antibodies to the cancer stem cells markers these nanoparticles may be delivered to the cancer tissue and mediate the laser induced thermolysis of the cancer stem cells that initiate and drive growth of cancer. This paper addresses the Lgr5 cell surface marker mediating the Wnt/β-catenin signal transduction as a potential target for anti-cancer laser immunotherapy of skin cancers.

Continuous-wave laser micro-beams are generally used as diagnostic tools in laser scanning microscopes or in the case of near-infrared (NIR) micro-beams, as optical traps for cell manipulation and force characterization. Because single beam traps are created with objectives of high numerical aperture, typical trapping intensities and photon flux densities are in the order of 10⁶ W/cm² and 10³ cm^-2s^-1, respectively. The main idea of our theoretical study was to investigate the thermal reaction of RBCs irradiated by laser micro-beam. The study is supported by the fact that many experiments have been carried out with RBCs in laser NIR tweezers. In the present work it has been identified that the laser affects a RBC with a density of absorbed energy at approximately 10⁷ J/cm³, which causes a temperature rise in the cell of about 7 – 12 °C.

We report the results of study of gold and silicon nanoparticles as contrasting agents for diffuse optical spectroscopy (DOS). Optical properties of the nanoparticles suspensions and model objects were obtained from spectrophotometric measurements in the wavelength range of 500-1100 nm. The DOS measurements were performed with a liquid phantom consisting of water, lipofundin and ink mixture providing optical properties of the solution close to those of biotissue. The phantom contained an inclusion filled with lipofundin and aqueous suspension of gold nanoparticles (GNPs) which were characterized by strong absorption in the red and near infrared spectral range. The inclusion contrast in the obtained DOS images was estimated, which allowed to consider the selected GNPs as potentially perspective contrast agents for DOS applications.

In the present study a new adhesive system with embedded PVP-stabilized nano-particulate silver markers has been designed. Nanosized silver was used as a radio-opaque contrast material in SEM examination of adhesive system in dentine. It was studied the impact of nano-particulate silver fillers on rheological properties of adhesive system and its penetration in dentine volume. A SEM comparative evaluation of resin replicas produced using adhesive system with embedded silver nanoparticles and that without ones was carried out. It was shown that embedding of silver nanoparticles into adhesive system did not make its penetration worse. It was established that embedding of nanosized silver changed adhesive system morphology. The methodology that allows visualizing interfaces and intermediate layers between dentine, adhesive system and restorative material using silver nano-particulate markers was developed and approved. Silver nanoparticles were used to compare the objective depth of penetration of adhesive systems of different generations in root dentine with differently oriented dentinal tubules, bonding resin delivery and gravity.

The correction of experimentally measured luminescence excitation spectra of the samples with ZnCdS nanoparticles using the algorithm based on Monte Carlo simulation of the transport of radiation through the sample was made. The studied samples differed in amount of scattering, packing density of nanoparticles and spectral dependence of scattering and absorption. It has been shown that the developed correction technique makes possible the more accurately determining of the position and the shape of excitation bands and also the detecting of features of the spectra in particular exciton excitation bands.

Spin systems consisted of single electronic spin S=1 of the NV center and nearby nuclear spins I=1/2 of ¹³C atoms disposed in diamond lattice near the center can be used as a small register of a quantum computer or as a sensor of a magnetic field. At odd number of nuclear spins eigenvalues of the spin systems at zero external magnetic field are at least twofold degenerated (Kramers degeneration) due to time reversal invariance of the spin Hamiltonian. This degeneracy is lifted only by external magnetic field regardless of the presence of any electric (crystal) field which can also lift the degeneracy thus hindering measurement of the magnetic field. Therefore, the Kramers-degenerated spin systems can be very perspective for measurement of a local magnetic field by the NV-based single-spin quantum magnetometer. Here, we are considering analytically the simplest Kramers-degenerated spin system NV+1¹³C consisting of a single electron spin S=1 of the NV сenter coupled by hyperfine interaction with a single nuclear spin I=1/2 of ¹³C atom disposed in arbitrary site of diamond lattice. Simple approximate analytical expressions are obtained for eigenvalues and eigenstates of the spin system.

We demonstrate a two-stage three-pass non-collinear optical parametric chirped-pulse amplifier delivering 125 μJ pulse energy at 20 kHz repetition rate, corresponding to an average power of 2.5W. The system is pumped by a 20 kHz Nd:YVO4 regenerative amplifier system. A grism-pair stretcher stretches the 6 fs seed pulses to more than 100 ps from 650nm to 1000 nm. The amplified signal pulses are compressed with SF57 and fused silica glass blocks. Using an acousto-optical programmable dispersive filter to compensate the residual higher-order dispersion pulses of 9.6 fs duration are obtained which corresponds to a peak power of 13GW. We estimate the level of parametric superfluorescence with the spectral hole technique.

The entanglement between two identical two-level atoms successively passing thermal cavity and interacting with one-mode thermal field through a degenerate two-photon process is investigated. It is shown that two atoms can be entangled through such nonlinear interaction.

The entanglement of two dipole-coupled atoms with nondegenerate two-photon transitions interacting with twomode field in lossless cavity has been investigated. It shows that the entanglement is dependent on the initial atomic states. The possibility of considerable growth of atomic entanglement due atomic coherence and dipoledipole interaction is shown in the case of great mean values of thermal photons.

We investigate the evolution of a quantum system described by the two-atom Jaynes-Cummings model with an intensity-dependent couplings by displaying the linear atomic entropy and the asymptotic behavior of state vector. The possibility of the system being initially in a pure disentangled state to revive into this state during the evolution process is shown. Conditions and times of disentanglement are derived.

The influence of chaotic behavior of coherent state (CS) parameters on entanglement dynamics in system of two level atoms and photons in cavity is investigated. The initial state of the system is chosen as factorized production of photon and atomic coherent states. To find a solution of the Schrödinger equation, we presented the time-dependent wave function in the form of a wave packet in CS representation. The phase portraits and Poincare sections for classical dynamics of CS were computed, and time dependence of the mean number of photons level populations and atomic entropy were calculated in quantum case. The analysis showed that the chaotic behavior in quantum-optical Dicke model increases the degree of entanglement in the atomic subsystem. At the same time greater entanglement is generated when selecting the initial atomic CS parameters near the center of the corresponding Poincare sections. It is considered dynamics of two identical two-level atoms in non-ideal cavity (nonideal Tavis-Cummings model). Accounting for decay showed that the generation of atomic entanglement is accompanied by the return of the initial separable state (”death” of entanglement), but this behavior with the increase of the initial parameter of the field CS is only at sufficiently small times. Influence of detuning and damping constants are considered.

The solution of Maxwell-Schrödinger equations describing superradiant scattering of light from a Bose-Einstein condensate of dilute atomic gas is analyzed. A novel method of control the generation of recoil atomic ‘clouds’ and scattered fields by inclined illumination of a Bose-Einstein condensate sample is proposed.

With the help of the numerical simulation it is shown that the probability density function of the phase difference in the two points of speckle-field in the far-field diffraction region can have the maximum for the values of 0 and π radians if the scattering object has symmetric aperture. The histograms of the statistical distribution of the phase difference in speckle-field in the far-field diffraction region are obtained numerically. The results of the numerical statistical experiments confirm the results of the natural experiments with the use of the Young’s interferometer.

When a surface is illuminated with a coherent light such as a laser beam, speckle pattern consisting of bright and dark regions is observed. It depends on the surface parameters and carries important information about the roughness of the surface. Various methods and techniques are employed for the determination of surface roughness parameters using other experimental techniques. In this paper, an experimental approach for surface roughness evaluation based on the speckle pattern imaging has been attempted by a simple configuration of setup consisting laser and CCD camera .The speckle image is processed by ImageJ software and the surface parameters like skewness, kurtosis and histogram have been studied. The technique reported here has a great potential for precise and non-contact optical measurements of rough surfaces.

We present the numerical study of terahertz generation via different frequency mixing in two-wavelength vertical external cavity surface emitting laser. Nonlinear crystal is placed inside the resonator to increase terahertz radiation power. The dynamical model is based on modified Lang-Kobayashi equations. Numerical simulation through varying round trip time in the external cavity and feedback rate is presented.

The numerical simulation results of the nonadiabacity display in electromagnetically induced transparency are presented. The Λ scheme of degenerate and inhomogeneous quantum transitions J = 0 → J = 1 → J = 2 is examined for the cases of slow and abrupt rises in the leading edge of the input probe radiation pulse. For circularly polarized radiations, it has been shown that the deviation from the condition of adiabatic sequence can lead to a separation of the probe pulse of the adiabaton into a train of subpulses. In the case of linear polarization of the input probe field and the circular polarization of the input control field, the probe radiation pulse is split into two pulses with opposite circular polarizations and a multispike structure of the envelopes. If an abrupt rise of the leading edge of the input probe pulse takes place the precursor pulse arises at a probe radiation frequency and the velocity of its propagation coincides with the speed of light in vacuum.

Results of supercontinuum generation experiments in case of excitation by optical pulses with central wavelength 828 nm, duration 40-50 fs, energy up to 1,0-1,5 mJ are presented. Supercontinuum radiation was detected in crystal DKDP and other crystals with χ⁽²⁾-nonlinearity at range from 400 nm to 1450 nm, as well as up to 2300 nm, where radiation within blue range 400-480 nm and IR-range 900-2300 nm was caused by parametric processes. Obtained radiation was analog of microstructured fibers supercontinuum radiation in the width of output spectrum.

By numerical simulation we investigate the non-stationary manifestations and nonlinear dynamics of frequency - modulated cw laser beam propagated in resonance conditions. At modulation periods comparable with the atomic relaxation times the time dependence of the output intensity exhibits the manifestations of the optical transient nutation and resonance self-action effects. In the present paper we analyse the effect of resonance self-action on optical nutation and its dynamical manifestations.

The creation of photo-integrated volumetric nonlinear micro-structures in amorphous materials is discussed. The theoretical consideration of the formation of the nonlinear-optical spatial structures with small periodicity in a volumetric geometry of the creation of their profiles and the detailed analysis of properties of the inserted nonlinear polarizability has been presented. The obtained results of the experimental investigations show that, in comparison with the widely known simple method of the creation of nonlinear-optical structures by means of the plane-parallel laser beams, the considered case of the volumetric creation, by means of the crossed Gaussian beams in a volume of a sample, gives the important advantage connected with possibility of a wide variation of properties for the induced polarizability in volumetric media, allowing to create small-scale micro structures of the photo-integrated anisotropy with the different dimensions. As a result, the possibility of the creation of the spatially homogeneous photo-integrated volumetric modulation of anisotropy in oxide glass materials has been experimentally demonstrated. The studied photo-integrated nonlinear-optical spatially-periodic micro structures may be useful in future for the creation of the various photonic devices.

The results of the observation and investigation of the light-induced photorefractive effect, which arises by the action of the powerful two-component laser radiation on volumetric isotropic medium, are discussed. It is shown, that the lightinduced photorefractive grating can be created by powerful light in some isotropic silicate glass materials in which the sufficiently effective diffraction of radiation is observed by that. The theoretical calculations and experimental results of the investigation of the diffraction of radiation on the light-induced photorefractive gratings in volumetric glass mediums are presented and the observed characteristic peculiarities are analyzed.

Steady-state operational characteristics of a dual-wavelength vertical external cavity surface-emitting laser (VECSEL) with a nonlinear quasi-phase-matched crystal placed in the laser cavity have been simulated. We have demonstrated the dramatic effect of three-wave nonlinear optical interaction on the intensity of both fundamental optical fields of the laser. Potential capability of the dual-wavelength VECSEL for efficient generation of midor far-infrared radiation by means of the intracavity nonlinear frequency down-conversion has been shown.

Samarium ion doped in rare earth crystals are spectroscopically interesting system since samarium has many atomic transitions in the visible range. Single crystals of samarium doped CdF₂ has been studied for its non linear behavior using the home made z-scan set up. The Z-scan technique is a simple experimental set up which can rapidly measures both nonlinear absorption and Non linear Refraction. This technique is versatile yet is highly sensitive and has gained rapid acceptance by the nonlinear optics community as a standard technique for measuring the non linear susceptibility χ⁽²⁾ or the χ(³⁾ according as the media is a χ⁽²⁾ system or the χ⁽³⁾ system.

In the effective mass approximation for electron (hole) states of a spheroidal quantum dot with and without external fields the perturbation theory schemes are constructed in the framework of the Kantorovich and adiabatic methods. The eigenvalues and eigenfunctions of the problem, obtained in both analytical and numerical forms, are applied to the analysis of the absorption coefficient for an ensemble of spheroidal quantum dots with random dimensions of the minor semiaxis and with parabolic or non-parabolic dispersion laws for holes and electrons, affected by a homogeneous electric field, i.e., the quantum-confined Stark effect.

We consider theoretically an electron-impact ionization process at high impact energy and large momentum transfer in the presence of laser radiation. The target is modeled as an electron bound by a harmonic potential. Dressing of the target state by the laser field is treated exactly. Laser-assisted differential cross sections are calculated using either Volkov functions or plane waves for incoming and outgoing electrons. It is shown that even in the case of the low-frequency and weak-intensity laser radiation the effect of the field on these electrons can dramatically influence the shape of the cross sections.

An indigenous laser light scattering spectrometer is being developed for the studies of biological cells, macromolecules and their interactions. A laboratory spectrometer is used and modified as scattering arm, Turn Table and Collimating arm. Both the arms have polarizers, one acting as polarizer and the other as analyzer. The scattered light from the scattering cell is analyzed by an analyzer and is fed to a PMT and a photon counting module. Except for the PMT all the accessories are being fabricated indigenously. The studies are based initially on the studies of red blood cells. Studies are focused on for their single particle and their aggregation behavior. Using the ORT program developed by Otto Glatter the morphology of red blood cells will be analyzed.