The extended sphere of the laser successful use at large vagueness of the gear of radiation interaction with biological and biosimilar objects is a main modern paradox in the application of low-intensity coherent radiation in biology and medicine. There are rather regularly, for example, the reasons of immateriality of such parameters as laser radiation coherency degree for biostimulation, but the replacement of semi-conductor lasers by the light diodes isn't observed in medical practice until now. there are also no convincing results on comparative analysis of biostimulated effect under coherent and noncoherent radiation. Action of coherent electromagnetic radiation of the visible and infrared spectral range causes, as appear, the same type structure-optical changes in various objects biological liquids, cells suspensions, model biomolecular solutions, cells of plan, insects and animals. The medicobiologic consequences of laser effect are extremely variable because of the complexity of biological object and sophistication of research techniques and analyses. The energy doze of radiation acting onto a bio-object, as a rule, is extremely small, and hence like the case of extremely high frequency radiation one can to name this action by the 'informative' one, i.e., initiating only biosystem reactions is produced due to its own energy. In connection with the relatively slow biosystem response to the laser radiation action, the nonlocality of this reaction at the local action and large variety of biochemical reactions caused with laser radiation one can assume the existence of uniform physical mechanism realizing the biostimulation effect of laser radiation for various biosystems.

The processes of the energy transfer between ionic dye molecules in model organized molecular systems were studied by the laser fluorescence spectroscopy. The possibility of regulation of the efficiency of the energy transfer by reorganization of molecular structure was showed.

The skin response was studied for different radiant exposure of short and long laser pulses and reaction to multipulse action using Er-glass laser radiation. Lesion ranging from a mild erythema to tissue coagulation were produced on porcine skin. Radiant exposure producing 50 percent probability of a particular grade of lesion were established. A dependence of ED50 of minimum erythema versus number of pulses and beam cross section were studied. The dose-response relationship for producing different grades of burns were determined for energy densities of single laser pulse within the range 0.5- 35 J/cm² and pulse duration 100 ns and 3 ms. The single pulse dose in a chain of repetitive pluses producing minimum erythema were determined for 2ⁿ(n equals 1-6 pulses). The minimum reaction of skin on laser irradiance were studied for different beam diameter. The reaction of skin is mostly considered as local super heating. The data obtained are adequate to update safety standards for cutaneous injury within thee ranges of radiant exposure and beam spotsize.

The degree of polarization of polarized light as it propagates through breast tissues depends on the type of tissue and light wavelength. This feature was used to image cancerous tissue where tumor was clearly distinguished from the normal tissue.

Conventional laser-induced fluorescence spectroscopy of endogenous chromophores like NADH and PP IX provides only uncertain information about the relative amounts of these metabolites in the observed cells due to varying optical tissue parameters. But for diagnostic applications the concentrations of these chromophores in many cases have to be determined quantitatively to establish a tissue- independent differentiation criterion. It is well-known that the individually and locally varying optical tissue parameters are major obstacles for the determination of the true chromophore concentrations by simple fluorescence spectroscopy. To overcome this problem, a fiber-based, 2- channel technique including a rescaled NADH-channel and a relative PP IX-channel was developed. The combined information of both channels can provide good tissue state separation. Ex-vivo studies with resected and frozen samples as well as in-vivo studies of squamous cells in the histologically confirmed states: normal, tumor margin, inflammation and hyperplasia were performed. At the identical tissue spot both, the rescaled NADH-fluorescence and the relative PP IX-fluorescence were determined. In the first case a nitrogen laser in the latter case a diode laser were used as excitation sources. In this study a good separation between the different tissue states was achieved. To obtain 2D quantitative fluorophore images of a certain tissue surface an even more sophisticated method is needed. At the moment a new rescaling method for VIS and IR light in the frequency domain is under construction. it can be applied within the validity range of the diffusion approximation and provides full (mu) _a and (mu) _s rescaling possibility in a 2D, non-contact mapping mode. The flying-spot device is planned to be used in combination with a standard operation microscope of ZEISS, Germany and will provide quantitative PP IX-fluorescence signals with a lateral resolution in the millimeter range.

Rayleigh light scattering brings a very rich information about static and dynamic parameters of macromolecules in the solutions including aqueous solutions of proteins. It is known that protein molecule have a big electric charge and great dipole moment connected with it. In our investigation it was shown that optic anisotropy, molecular mass, coefficient of molecular interaction, molecular mobility are varied non-linearly with changing of net charge of macromolecules. On the base of our researches we proposed a simple, affordable optical method of diagnostic of oncological diseases and predisposition.

New decision of laser radiation injection into visual channel of photoprojector is presented. High spatial resolution of laser stimulation of biological object is caused by the surposing of formed laser beam with magnified object's image on surface photoprojector screen. The examples of N₂-laser and Ar-laser radiation injection are considered.

Optical and acoustic beams are known to be useful for medical and biological applications, such as diagnostics, surgery, etc. At high intensities both nonlinear lens effects and nonlinear absorption can be significant for the beams. The nonlinear absorption arises due to two-photon optical processes or acoustic shock wave formation. The present work is devoted to the theoretical description of nonlinear beam propagation and focal spot formation taking into account the competition between focusing, diffraction and absorption. We derived a new nonlinear integro- differential equation describing the spatial evolution of the beam width. The general analytical solution of this equation is obtained for arbitrary boundary conditions. The simple formulas are derived for the angle divergence in the far field, as well as for beam width at nonlinear waist. The results of the analysis of these key parameters in different situations are presented.

There are many problems with current environmental sampling and analysis programs. Foremost among these problems is the need to collect many samples in order to obtain the desired accuracy of the characteristics of interest. Other concerns involve inadvertent changes that may affect the sample characteristics between sample collection and analysis. The high cost of analyzing trace levels of organic and metallic toxicants is also restrictive. This paper summarizes sampling and analytical needs, based on current limitations of procedures and instrumentation, that may possibly overcome using laser-based procedures. These needs include current shortcomings in water and wastewater analyses, specifically problems with sample collection, preparation, and analysis. The use of inexpensive and fast instrumentation, especially if the procedures minimize sample preparation and can be used in-situ, will vastly improve environmental research and characterization efforts by enabling greatly increased sample sizes with better spatial and temporal resolution. Current research being jointly conducted by the Department of Civil and Environmental Engineering and the Department of Physics at the University of Alabama at Birmingham, Laboratory of Laser Spectroscopy of Solids at the General Physics Institute of the Russian Academia of Science, and Alabama Laser Technologies, is demonstrating he use of several configurations of laser-based instruments to cost- effectively analyze very low levels of toxicants. This National Science Foundation sponsored research effort has recently demonstrated the detection of copper and lead at low (mu) g/L levels using atomic laser fluorescence using a tunable color center laser, spectrometer, intensified TE- cooled CCD camera, and atomizing furnace. Fluorescence/Raman spectroscopic instrumentation with a He-Ne and/or Alexandrite laser, portable spectrograph and CCD camera has also been developed for qualitative characterization of water and solid waste samples.

Results are presented from three different applications of laser induced breakdown spectroscopy (LIBS) in problems of environmental interest. In one case, LIBS is applied in the on-line control of the nickel recovery process, by monitoring the nickel content of molten ferronickel slabs, in a laboratory scale experiment. In a second case, LIBS is used in the identification of polymer materials, and on the basis of spectral features, criteria are proposed for the distinction among different types of plastic materials. Also, in preliminary experiments, the use of LIBS with respect to the detection of heavy and toxic metals in paints and the possibility of performing depth profile analysis of multiple paint layers is examined.

Aromatic hydrocarbons are important and dangerous pollutants of the aquatic environment. With the method of laser-induced fluorescence it is possible to detect Benzene, Toluene, Xylene (BTX) as well as Polycyclic Aromatic Hydrocarbons (PAH) sensitively. The detection of these molecules by a continuously working in-situ method is achieved by combining LIF with fiberoptic guidance of light. We presence results on the detection of BTX and PAH by excitation with 266 nm and 355 nm radiation from a diode-pumped solid-state laser especially developed for sensor applications. The system is operated with thermoelectric cooling and battery supply independent of any installations is projected. The laser delivers pulses of 7 ns/140 (mu) J in the UV at a repetition rate of 100 Hz. Using time-resolved and spectrally-resolved detection of the fluorescence signal, the system delivers information that can be used to discriminate between BTX and PAH-molecules. We have also performed extensive investigations of the influence of scattering particles on the sensor signal. This led to specific optimizations of the sensor-head for different applications.

Two methods (the dynamic light scattering and the luminescence probe technique) are used for the investigation of the structure of water systems. The study of dynamic light scattering leads to the conclusion that the water systems have a cluster structure, the volume of which depends ont he temperature. More detailed information of water biological systems is obtained from the analysis of the luminescence data. The analysis of the water solution structure was carried out on the base of an experimental excitation energy transfer process. It was shown that the water matrix structure is the main factor of the efficiency of such processes.

Several methods (particle counting and sizing, (beta) -ray absorption monitoring, gravimetric measurements, microscopy) were all applied to study the airborne dust particle pollution in Budapest, at various locations and during different seasons of the year. In addition, the airborne dust particle concentration was determined at several altitudes and several locations as a function of particle size. The results obtained by different measurements demonstrate that in certain cases the measured pollution exceeded the values permitted by Hungarian health standards.

The importance of immunodeficiency problem has increased last time not only due to AIDS appearance, but also to a great extent as a result of the development and active practical use of the methods of immunology parameters investigations. Al great pharmaceutical firms are organizing the process of creating the drugs, influencing on the different phases of immunity, but unfortunately, the problem of their adverse effect and connected complications is till today a milestone. A great number of investigations, proving a good effect of laser-magnetic therapy concerning immune system have been done today. There is, in particular, changing of blood counts and immunologic tests after intravenous laser irradiation of blood. Intravenous laser irradiation of blood results in increasing of lymphocytes, T-immuno stimulation, stabilization of t-lymphocyte subpopulation, increasing of t-lymphocyte helper activity and decreasing of suppressor one.Under this laser action number of circulating immune complexes is decreased, and blood serum bactericide activity and lisozyme number are increased.

Acute inflammation of epididymitis (AE), which can be met as separately and also with an acute iifflammatory process in testicle-epithdymo-orchitis (AEO) is most often met of men's urological diseases. Also, the critical and sometimes lethal complications of epididymo-orchitis are erase- bacteriological shock and urosepsis1'2. AB and AEO transferring to a chronic diseases can also cause serious causes for men's copulative and reproductive function. However, specialists thoughts regarding choosing the AE and ABO method treatment are still not the same and the results are not satisfactory.

Hydroxyapatite (HA) is a ceramic material which is intersecting as a coating of Titanium protheses because of its biological compatibility. The characteristics of the HA films deposited by pulsed laser ablation are influenced by a large number of process parameters. After the deposition HA film show also an ageing effect related to changes of the film properties. The knowledge of the refractive index of HA film could help to identify the properties both during the film growth and, after the deposition, during the exposure to different environments. The HA films were deposited on Ti substrates and optically characterized in the 500-850 nm optical spectrum by spectroscopic ellipsometry and the resulting refractive indices are reported in the paper. Starting from the results of SEM and XRD measurements a suitable model was developed that allowed the solution of the ellipsometric equations in terms of n and k over the entire measured spectrum at 65 degrees and 75 degrees incidence angles.

Thin films of hydroxyapatite were created on flat, polished Ti6Al4V substrates by pulsed laser deposition. Results of physical analysis and in-vitro analysis are presented and discussed.

Solid state lasers make possible rapid technological advances in medical applications by virtue of their wavelength and temporal mode versatility, convenience, relative coinpacmess, and portability. The possibility of using solid state laser radiation in ophthalmology, dentistry and dermatology is discussed and analyzed.

Results of application of the Cr4+ doped crystals as Q- switches and nonlinear media for four-wave mixing in Nd- lasers are presented. Cr4+ centers demonstrate unique properties which give rise to use of the Cr4+ doped crystals both as active media and passive elements of laser resonators. Lasers based on these active media demonstrate tunable lasing in the near infrared range 1.1-1.6 microns. This spectral region is very interesting for environmental monitoring applications. Passive elements made of the Cr4+ doped crystals are mainly used as Q-switches for Nd- lasers operating in 1 micron region. Another possibility is to use these elements for preventing lasing in 1 micron range to make more easy the operation of Nd-lasers on the weak transitions. Both these wavelength are very interesting for medical applications. In this case Cr4+ centers can be formed directly in the active rod. So the rods with combination of active and passive properties could be produced. The newest form of applications of crystals with Cr4+ centers is the use of it as nonlinear media for four-wave mixing in Nd-lasers. New optical schemes of resonators, designed to use these modern decision, enable us to create Nd-lasers with a very low beam divergence which can be used for lidars to monitor the pollutions.

We report on investigation of mode-locked regime in tunable Cr⁴⁺:YAG laser. Our experiments have been performed using Nd:YAG laser for pumping Cr⁴⁺:Y₃Al₅O₁₂ laser. We have obtained mode-locked generation of tunable radiation in the range from 1,350 to 1,550 nm. There was a generation with pulse duration in ps range and repetition rate of 320 MHz. Using a 0.5 percent transmitting output mirror, as high as 305 mW of useful output power at 1.5 micrometers was obtained from the laser with 5.5 W of absorbed pump power. The laser has threshold for mode-locked regime near 7 W for synchronous mode locking and 5 W for active mode locking. We have analyzed the laser system with Kerr lens feedback in the phase trajectory of five-dimensional space. The computer simulation have shown the presence of asymptotically stable stationary point in behavior of temporal Gaussian beam similar spatial mode structure in the resonators, when the temporal mode does not change passing through all dispersion element in laser. Our calculations show that the sign of dispersion is very important for formation of phase portrait in our laser system. In conclusion, we have demonstrated Cr⁴⁺:YAG laser operation in mode-locked regime on the edge of stability region. The analysis of the solutions in our model reveals that chaotic instabilities can be reached through increasing of non-linear interaction temporal and spatial Gaussian beam. The characteristics of this laser systems can provide the source of laser radiation for diagnostics and therapy.

Solid state (SS) tunable LiF:F₂ color center laser with second and fourth harmonic generation for visible and ultra violet spectral ranges was developed for the laser induced fluorescence spectroscopy (LIFS). The construction and properties of excitation, registration and flame atomization systems for water solution diagnostic are discussed. The testing experiment with low iron concentrated water sample exhibits ultrahigh sensitivity which was estimated to be 0.05 ppb in our set-up. The SS LIFS spectrometer developed is usable to measure more than 42 metal elements in solution on the ppm, ppb level for various medical and biological applications.

One of the most promising and easy-to-realize designs of gas laser with high specific output power and a small-size laser head involves a transverse RF discharge in a narrow gap between two wide, parallel electrodes(the slab configuration of discharge) and a hybrid waveguide-unstable resonator [1 II. Tn the present work we describe prototypes of smallsizc 3O and 5OW CO2 slab lasets with waveguide-unstable resonators, which can be considered as basic designs for industrial production. We investigated the output-power parameters of these lasers. Furthermore, we examined the spectral characteiistics of the lasers and the possibility of tuning the radiation wavelength in a wide range. The CW Ar-Xe laser with RF excitation is described. The applications possibilities of these lasers in medicine and remote sensing are discussed.

An approximate solution of the equations governing collinear acousto-optical interaction in terms of confluent hyper- geometric function is obtained under conditions of plane- wave approximation. However, the experimental acousto- optical devices deal with a beam of finite dimensions which imply a substantial transversal and longitudinal inhomogeneity altering considerably the results of diffraction. A theory of such quasi-collinear interaction is suggested. An acousto-optical tunable filter is one of most promising devices using acousto-optical diffraction and able to ensure high-resolution spectral analysis of natural optical radiations could further be improved if two instead of one consequently arranged crystals were used in the acousto-optical cell.

To measure the shape of the cornea and its declinations from the necessary values before and after PRK operation, s well as the shape of other spherical objects like artificial pupil, a technique was used of double-frequency dual-beam interferometry. The technique is based on determination of the optical path difference between two neighboring laser beams, reflected from the cornea or other surface under investigation. Knowing the distance between the beams on the investigated shape. The shape itself is reconstructed by along-line integration. To adjust the wavefront orientation of the laser beam to the spherical shape of the cornea or artificial pupil in the course of scanning, additional lens is involved. Signal-to-noise ratio is ameliorated excluding losses in the acousto-optic deflectors. Polarization selection is realized for choosing the signal needed for measurement. 2D image presentation is accompanied by convenient PC accessories, permitting precise cross-section measurements along selected directions. Sensitivity of the order of 10^-2 micrometers is achieved.