Recognition of aerosol clouds material at some significant distance is now a key requirement for the wide range of applications. The elastic backscatter lidar have demonstrated high capabilities in aerosol remote detection, cloud real-time mapping at very long distances for low-concentration natural aerosols as well as artificial ones [1]. However, recognition ability is required to make them more relevant. Laser-induced fluorescence (LIF) looks very promising with respect to the recognition problem. New approach based on mobile lidar complex [2] equipped by spectrally-and range-resolved LIF-sensor is described as well as some results of field tests. The LIF-sensor consists of four-harmonics Nd:YAG laser equipped by an output expander to provide final beam divergence <1 mrad, 500-mm aspheric Cassegrain-type multi-wavelength receiving telescope, set of single-element receivers for measurement of the elastic backscatter radiation, and multi-element receiver with monochromator for spectrally-resolved LIF measurements. The system is equipped by 2-axis scanning mirror and variable-FOV video-camera collimated with the lidar scanning direction. The LIF-lidar is mounted on a truck-based platform (20-feet container) as a part of multi-purpose mobile lidar complex and adjusted for field conditions.

Optical diagnostics of laser ablation plasma has provided the opportunity to realize calibration-free analyses of solid and liquid materials. In general, this variant of optical emission spectroscopy of pulsed plasma allows the matrix effects to be overcome, yielding satisfactorily precise and accurate quantitative results on elemental composition of materials without using calibration curves, certified reference materials, and internal standards. Such analysis for solids is very close to be nondestructive due to the minimum possible ablated mass, a feature which is very important in many applications, especially for unique museum exhibits and jeweler samples. In this paper, the use of the method for the analysis of elements mainly in metallic alloys, glass samples, and archaeological findings is demonstrated. The results presented confirm the suitability of the approach for routine applications of our instrumentation, while at the same time simplifying the overall analytical procedure.

Data of aerosol measurements from October 2004 to December 2006 and a collection of back trajectories arriving at a monitoring site at the measurement instants were used to reveal main aerosol source areas with the help of the residence time analysis. Overall aerosol content in the vertical atmosphere column was measured in Minsk (Belarus) and Belsk (Poland) with the help of multiwavelength aerosol lidar and sun-scanning spectral radiometer. 3D five day back trajectories were calculated using wind field data provided by Republican GidroMeteoCenter of Republic Belarus. These data were supplemented with the vertical velocity data and the wind field in the planetary boundary layer. It was found that the most powerful aerosol source areas are beyond of Belarus and Poland territories. They are on the south-east, south and south-west directions to monitoring stations. Revealed sources are close to the expert EMEP aerosol emission data. On the average the south territories affect the most atmosphere conditions at the monitoring sites. About 60% of aerosols in Minsk and about 50% of aerosols in Belsk have a transboundary origin.

Extinction of radiation in the marine boundary layer is dominated by scattering and absorption due to atmospheric aerosol. It is known, that the extinction of optical radiation visible and near IR spectra in the marine surface layer is determined mainly by scattering and absorption atmospheric aerosol. It influences on a dependence of spectral transmission and extinction both natural, and artificial light that is of interest for a wide range of problems, in particular for radiating problems at studying laws of climate formation, and for lines of the applications connected to the forecast of a signal power in coastal conditions at an estimation of EO systems characteristics. This is important to optical retrievals from satellite, remote sensing at environmental monitoring, backscatter of light to space (including climate forcing), cloud properties etc. In unpolluted regions the greatest effects on near shore scattering extinction will be a result of sea-salt from breaking waves and variations in relative humidity. The role of breaking waves appears to be modulated by wind, tide, swell, wave spectra and coastal conditions. These influences will be superimposed upon aerosol generated by open ocean sea-salt aerosol that varies with wind speed. The focus of our study is the extinction and optical effects due to aerosol in a specific coastal region. This involves linking coastal physical properties to oceanic and meteorological parameters in order to develop predictive algorithms that describe 3-D aerosol structure and variability. The aerosol microphysical model of the marine and coastal atmosphere surface layer is considered. The model distinctive feature is parameterization of amplitude and width of the modes as functions of fetch and wind speed. In the paper the dN/dr behavior depending at change meteorological parameters, heights above sea level, fetch, wind speed and RH is show. On the basis of the developed model with usage of Mie theory for spheres the description of the last version of developed code MaexPro 5.0 (Marine Aerosol Extinction Profiles) for spectral profiles of aerosol extinction coefficients α(λ) calculations in the wavelength band, equal λ = 0.2 - 12 μm, with step Δλ= 0.0001 m is presented. Also α(λ) profiles for various wind modes (combinations X and U) calculated by MaexPro 5.0 code are given. Results of α(λ) profiles calculations are presented at change RH = 40 - 98 % and heights H = 0 - 25 m. The calculated spectrums of α(λ) profiles are compared with experimental data of α(λ) received by a transmission method in various geographical areas.

Results of analysis of lidar returns from clouds obtained using incoherent spatial filtering are presented in the paper. A correspondence of multiple scattering contribution estimations from experimental data with model ones is obtained. Calculations of clouds optical parameters and cloud's effective droplets size from experimental data are presented.

Revelation of ions hydration in water Raman spectra was investigated. The rows of ions influence concordant with properties of ions hydration on qualitative level were established. Remote method of identification of salts and determination of their concentration was elaborated using artificial neural networks.

The long-term variations of the total column ozone amount, temperature in tropostratophere, UV-radiation above Kyrgyzstan and solar activity are analyzed. The deviations of monthly average meanings of UV-radiation from norm are presented, the anomaly periods are allocated. These data are analyzed for 22 and 23 cycles of 11-year solar activity. The parameters of solar activity such as the variations of sunspot numbers, their century amplitudes and their deviations, and also short-term deviations from smoothed 11-year's variations are analyzed. The reasons of increase of temperature in lower atmosphere connected with natural and antropogeneous factors and the existing forecasts of climate change are discussed [1,2]. The connection between variability of solar activity for the period from 1950 up to 2006 including 18-23 cycles of 11-year solar activity and the forecast of solar variability till 2060 and basic climate making parameters of atmosphere such as ozone variations, ultra-violet radiation, and temperature of tropostratosphere is analyzed. It is supposed that the significant decrease of solar activity level can result essential changes of temperature regime in troposphere. The high level of correlation between solar flair activity and UV-radiation is revealed. The increase of UV-radiation level takes place in periods of increasing of solar flair activity. The analysis of long-term changes of temperature regime of the lower stratosphere at levels 16 and 22 km has shown, that the total decrease of temperature corresponds to total decrease of ozone concentration. Thus the sharp changes of ozone concentration correspond to sharp decrease of temperature. In troposphere in this period the constant increase of temperature is observed. This fact illustrates a principle of compensation of atmospheric processes.

Here we are presenting the basic theoretical consideration to measurement of turbulence characteristics from observations of the onboard a flying aircraft. The method allows to record the integral turbulence intensity and two components of wind velocity along the optical path. The variance of the jitter of astronomic images is a measured characteristic. This paper presents the basic theoretical equations, needed for the measurement of turbulence characteristics from observations of the jitter of astronomic images from onboard a flying aircraft. The method allows us to record the integral turbulence intensity along the optical path. The variance of the jitter of astronomic images is a measured characteristic. This characteristic is thoroughly studied and stable to measurement errors.

Regular measurements of tropospheric aerosol parameters have been performed from January 2002 to May 2007 at Lidar Station Teplokluchenka, Kyrgyzstan (42.40° N, 78.50° E). A combined multiwavelength and Raman lidar was used to measure profiles of the aerosol backscatter and extinction coefficients, depolarization ratio and structure of the planetary boundary layer. The statistical analysis of aerosol optical properties was made both for the planetary boundary layer and for the free troposphere. Data on the aerosol backscatter profiles, which characterize a typical variation of vertical aerosol distribution, were selected for analysis. The results show seasonal values of the aerosol backscatter coefficient and the backscatter ratio in a mountainous region of Central Asia. Mean aerosol optical characteristics are estimated. Diurnal cycles of the planetary boundary layer optical characteristics are also presented. The particularities variability of optical and microphysical characteristics of the dust aerosol are revealed. The particle size distribution function and the complex refractive index have been found using the measurements of the aerosol backscattering coefficient at three wavelengths and the extinction coefficient at one wavelength. The dust events contribute significantly to very large aerosol backscatter and extinction coefficients in the boundary layer. The large masses of the dust aerosol are transported from Aral Sea basin and Middle East.

In modern conditions of power consumption growing in Russia, apparently, it is difficult to find alternative to further development of nuclear power engineering. The negative party of nuclear power engineering is the spent fuel of nuclear reactors (radioactive waste). The gaseous and fluid radioactive waste furbished of highly active impurity, dumps in atmosphere or pools. The highly active fluid radioactive waste stores by the way of saline concentrates in special tanks in surface layers of ground, above the level of groundwaters. A firm radioactive waste bury in pods from a stainless steel in underground workings, salt deposits, at the bottom of oceans. However this problem can be esteemed in a positive direction, as irradiation is a hard radiation, which one can be used as a power source in nuclear - optical converters with further conversion of optical radiation into the electric power with the help of photoelectric converters. Thus waste at all do not demand special processing and exposure in temporary storehouses. And the electricity can be worked out in a constant mode within many years practically without gang of a stimulus source, if a level of a residual radioactivity and the half-lives of component are high enough.

The humic substances (HS) are always present in the natural waters to a greater or lesser extent. Their property to fluorescent while being excited optically can be applied to use humic substances as a water ecosystem natural indicator. To realize the possibility of using HS as an natural indicator it is necessary to ascertain the correlation between the fluorescence characteristics of HS, their fluorophore structure and the genesis of HS with the influence of the parameters of the environment. It is also important to analyze these rules in the water surface micro-layer which is very important in the mass exchange between the hydrosphere and atmosphere (and in the pollution transfer also). The results of the determination of the molecular photophysical parameters of the HS fluorophores of different genesis are presented in the paper. The non-linear and kinetical fluorimetry methods with variation and artificial neural net algorithms were applied. During the research were solved the inverse problems for which the kinetic fluorescence curves were taken as an initial data. The curves were obtained through the HS excitation with the third harmonic of Yag-Nd Laser. The differences in the meanings of these parameters are discovered. The precise analysis of the shape of HS fluorescence band is accomplished. The results of this analysis are used to determine the structure of the water masses using the fluorescence characteristics of HS. The differences of the HS fluorescence characteristics in the water surface micro-layer and in the water volume is discovered. The ability of determining the structure of water micro-layer by laser probe is shown. The significant investigation result is the possibility of distinguishing the small fluorescenting anthropogenic admixture from the intense HS fluorescence background.

Glucose sensing and odorant molecules sensing are used as a models to explore the advantages and problems deriving from the use of either enzymes or odorant-binding proteins to develop stable optical biosensors. We report on a novel approach to address the problem of substrate consumption by sensors based on enzymes, namely the utilization of apoenzymes as non-active forms of the protein which are still able to bind the substrate/ligand. We also show studies in which the isolation of an odorant-binding protein from the nose of the dog is used as non-consuming analyte probe for the realization of an integrated optical sensor.

Lanthanide-sensitized luminescence is very attractive because the intramolecular energy transfers between the absorbing ligand and the luminescent ion results in strong narrow-band fluorescence with a large Stokes' shift and long decay times. We will report about several sensor systems based either on sol-gel materials or lanthanide chelates for monitoring and controlling water parameters, such as heavy metals, amines, phosphates.

The results of development of the method of fluorescent proteins investigation are discussed. Photophysical parameters and concentrations of the chromophores of protein mRFP1 have been determined with use of non-linear fluorimetry.

As demonstrated by the performed studies, the molecules of tricarbocyanine dye in vivo are localized in the low-permittivity region of the medium, predominantly in the form of contact ion pairs. Comparison of the experimental data and numerical simulation results has revealed that deformation of the dye fluorescence spectrum upon photochemotherapy is due to an increased percentage of methemoglobin (up to 50%) in the total hemoglobin concentration of a tumor tissue. A change in the photosensitizer fluorescence spectrum is observed in the area of a tumor, where laser radiation affects necrosis of the tissues. An analysis of the spectral data enables one to predict a depth and extent of the developed tumor necrosis. With the use of spectral methods, the treatment effectiveness may be optimized by the proper selection of an optimum dose and power density for photoexposure in the process of chemotherapy, with due regard for the character of pathology and individual features of a patient.

The size reduction for the photoacoustic cell can facilitate detection of small gas flows. The aspects (theoretical background, advantages/problems, possible implementation ways and applications) associated with the miniaturization are analyzed.

Although fiber optics have been applied in optical communication and sensor systems for several years in a very successful way, their first application was developed in medicine in the early 20's. Manufacturing and developing of optical fibers for biomedical purposes have required a lot of research efforts in order to achieve a non-invasive, in-vivo, and real-time diagnosis of different diseases in human or animal tissues. In general, optical fiber probes are designed as a function of the optical measurement technique. In this work, a brief description of the main optical techniques for optical characterization of biological tissues is presented. The recent advances in optical fiber probes for biomedical diagnosis in clinical analysis and optical biopsy in relation with the different spectroscopic or tomographic optical techniques are described.

A selection is presented of fiber-optic and micro-optic devices that have been designed and tested for guaranteeing the quality and safety of typical foods, such as extra virgin olive oil, beer, and milk. Scattered colorimetry is used to authenticate various types of extra virgin olive oil and beer, while a fiber-optic-based device for UV-VIS-NIR absorption spectroscopy is exploited in order to obtain the hyperspectral optical signature of olive oil. This is done not only for authentication purposes, but also so as to correlate the spectral data with the content of fatty acids, which are important nutritional factors. A micro-optic sensor for the detection of olive oil aroma that is capable of distinguishing different ageing levels of extra virgin olive oil is also presented. It shows effective potential for acting as a smart cap of bottled olive oil in order to achieve a non-destructive olfactory perception of oil ageing. Lastly, a compact portable fluorometer for the rapid monitoring of the carcinogenic M1 aflatoxin in milk, is experimented.

Different approaches to constructing sensing units based on nucleic acid (DNA) molecules are considered. These sensing units permit the detection of biologically relevant compounds of various origin. However, the main goal of this report is the description of the peculiarities of multifunctional sensing units based on particles of liquid-crystalline DNA dispersions immobilized in hydrogel. In combination with a portable dichrometer these sensing units form a new type of the bioanalytical system.

New true direct methods of sensitive real-time recording of molecular reactions on a surface and detection of bio- and chemical agents have been developed. The methods are based on measuring changes of thickness of a sensor layer due to binding reactions. A transparent plate or a gap between two surfaces of optical materials is used as the sensor layer. The methods allow employment as biochips of microscopic glass slips without deposition of any metal or dielectric films. Alternatively, direct pumping of liquid samples through the sensing gap with deposited recognition layers can be used. For label-free biosensing, different optical schemes were realized to record thickness changes due to receptor-ligand bindings with picometer-scale resolution. Biosensors named one-dimensional Picoscope^TM and Affinoscope^TM have been developed for real-time detection of several biological agents by different recognition spots or wells with specific receptors on the biochip surface. The devices have been successfully employed for detection of food pathogens, for investigation of pharmaceutical substances, for epitope mapping of different monoclonal antibodies and immunotherapy research, for monitoring of bacteriocin production, etc. Application of the devices can be as wide as that of optical microscopes as they provide standard lateral resolution and, in addition, offer much more comprehensive information with outstanding real-time resolution in depth, e.g., for measuring molecular binding kinetics, monitoring of assembling in molecular structures, etc. The Picoscope technology significantly increases power of research instruments for bio-, nano- and pico-technologies.

Thioflavin T (ThT) is known to have a very low quantum yield in water solutions itself and in the presence of native and denatured proteins and their amorphous aggregates, but to form a highly fluorescent complex with amyloid and amyloid-like fibrils. A new view on ThT spectral characteristics and mechanism of interaction with amyloid fibrils was elaborated on the basis of experimental studies of solvent polarity and viscosity influence on ThT absorption, excitation and fluorescence spectra and results of quantum-chemical calculations. It was shown that presence of the methyl group at nitrogen atom in benzthiazole ring makes nonplanar conformation of ThT energetically profitable and decreases barrier of intramolecular rotation of benzthiazole and aminobenzole rings relative to each other. Due to this ThT represents a dynamic set of molecules with differently perturbed systems of π-conjugated bonds. Possibility of torsional oscillations of ThT fragments relative to each other coupled with intramolecular charge transfer in the excited state permits to refer ThT to the class of molecular rotors. The significant, by three orders, increase of quantum yield of ThT when incorporated in amyloid and amyloid-like fibrils is caused by restriction of torsional oscillations of ThT fragments relative to each other.

Based on the conditions of alowable angular sampling of interfering waves, monochromatic multiple imaging systems with replicating spatial-frequency filters in the form of Fabry-Perot Interferometers, concentric ring masks, and diffractive multifocal lenses are compared with each other in their performance. Though these systems are shown to realize the same effect of multiple equidistant imaging, the forms of manifestation of the effect are not identical due to the difference in spectral content of the wave fields produced by the systems. The most perfect systems are found to be those with pure-phase diffractive multifocal lenses. First of all, they benefits from the extremely high total light efficiency and the sharply defined longitudinal localization of the visualized object space defined by the efficient focal depth. This enhances considerably the brightness of reproduced images and decreases their parasitic diffraction dispersion, background noise, and blurring.

The technical devices of explosives trace detection are discussed in this work. The attenuated total reflection method (ATR) is considered for detection of explosives traces on different things (documents, clothes, fingers). The results of experiments with Fourier spectrometer and ATR attachment for explosive trace detection are presented. The optical scheme and design of the compact testing device are discussed. The device includes the document information scanner and at the same time - the trace detector of explosives on the document cover.

In this paper we report on the possibility to design the luminescent molecular thermometer for the cryogenic temperatures. The approach is based on the high temperature sensitivity of the Pd-porphin phosphorescence in n-alkane matrices. The dependence of radiative deactivation of Pd-porphin triplet states on temperature has been studied in Shpol'skii matrices in the temperature interval of 1.2-210Κ . The dramatic changes in the phosphorescence spectra were observed upon temperature rise, which were due to inclusion of the thermally activated states of Pd-porphin in the processes of radiative deactivation. At liquid helium temperature T₁→S₀ emission is observed only, and an increase in temperature leads to the activation of T_i→S₀ radiative transitions, so new additional bands appear. Activation energy E_a of these states has been measured in n-octane and n-nonane matrices. The splitting value of the lowest quasidegenerate triplet state ΔE(T₂-T₁) has been determined for both planar and distorted conformations of Pd-porphin macrocycle in noctane matrix, amounting to 40 and 57 cm^-1, respectively. The workability of dependence of Pd-porphin phosphorescent properties on temperature in the design of the molecular thermometers for the temperature range from few K up to temperatures close to the melting point of n-alkane matrix (150-200 K) was shown.

The Raileigh back scattering of a highly coherent laser pulse in a single mode optical fiber has been simulated. An array of retro reflectors was used to simulate a scattering medium. Both amplitude and phase of the reflected waves were random. It has been shown that the reflectometry signal is not smooth (exponential) as in a usual non-coherent reflectometer. About 100 percent contrast in a chaotic signal is achievable provided the laser has single frequency, i.e. generation spectrum is limited by pulse duration. This chaotic signal nevertheless is stable in time if phase changes in the sensing fiber are negligible. Any mechanical impact leads to a phase shift in the sensing fiber. Due to local interference scattering signal changes, the location of impact can be easily calculated knowing light velocity in the sensing fiber. In our model, a harmonic in time mechanical influence was applied to the fiber pointwise. The sensitivity in different points of the fiber is quite random, and the same low amplitude impact may be transformed to a positive, negative or nearly zero signal. The reasons of such behavior are discussed as well as the methods to enhance the system sensitivity. The results of computer simulations were compared with experimental data and satisfactory conformity was obtained. In conclusion, the coherent optical time domain reflectometry seems to be very prospective for development of intrusion sensing systems of high (interference) sensitivity, precise impact localization, low error rate and low cost.

The derivation of the Sh-matrices using the T-matrix method allows the shape-dependent parameters to be separated from size- and refractive-index-dependent parameters. This separation also allows for the surface integrals to be solved and for analytic solutions to the light-scattering from some irregular morphologies to be found. In this manuscript we derive solutions for capsule-shaped and bi-sphere particles. We analyze the two-dimensional patterns resulting from these two different simulants of B. subtilis spores. The large differences between the patterns suggest that simple approximations to complicated particles may not be adequate.

The formation conditions for holographic gratings in photopolymeric material based on PMMA and phenanthrenequinone featuring high diffraction efficiency and thermal stability are established. The possibilities for their use in radiation coupling systems for planar lightguides are demonstrated.

We report the results of experimental investigation of changes induced by incoherent light with the wavelength of 625 nm in the spectrum of optical absorption in Bi₁₂TiO₂₀:Cd crystal. Semiconductor light diodes emitting quasimonochromatic radiation in red (λ = 625 nm) ranges of the spectrum were used as light sources. It is established that the irradiation of the bismuth titanium oxide crystal by noncoherent light with λ = 625 nm leads to change of a spectrum of optical absorption. In darkness conditions the relaxation of the induced changes proceeds during more than 120 hours. We used a model of light-induced absorption that includes four trap centers having the normal distributions on the energy for their concentration. This levels are populated by electrons light-exited from donors to the conduction band. This model makes possible the adequate approximation for spectral dependences of induced absorption, which are relaxation. The some parameters of defect centers in Bi₁₂TiO₂₀:Cd crystal are determined.

In low-polarity solvents the yield of the formed singlet oxygen is higher for the molecules of polymethine dyes (photsensitizers used in chemotherapy), with the anions which contribute to the ionic equilibrium accenting towards the increased portion of contact ion pairs and also with the anions containing heavy atoms.

The photoinduced absorption in Bi₁₂TiO₂₀ crystals is considered based on a model of two long-lived levels. Methods to control this effect and the ways of its application are presented. New possibilities for the realization of an optical memory system based on this effect are demonstrated.

The filament core of a femtosecond laser pulse propagating in an optical medium has extra-ordinary quality for exploitation that includes high quality tunable pulse generation from the UV to the THz. The peak intensity inside the filament is also high enough to dissociate/ionize any molecules resulting in remarkably distinct spectra which can be use for remote sensing of Chem-bio agent.

We report the recent progress in femtosecond filamentation and supercontinuum generation research at the Shanghai Institute of Optics and Fine Mechanics, including temporal evolution of plasma channels in air, generation of intense few-cycle laser pulses by cascaded filamentation, and enhanced supercontinuum generation in silver-nanoparticle-doped water.

Focused femtosecond laser pulse inside the bulk transparent materials leads to filamentary propagation. The optical intensity in the filamentary volume can become high enough to induce permanent structural modifications. The induction of filamentary structural modifications is a versatile technique for the fabrication of three-dimensional photonic devices in transparent materials. In this paper, we present applications of filamentation in microprocessing by demonstrating the fabrication of waveguide devices and diffractive optical elements in transparent materials. Filamentation is applied to micro welding of transparent substrates.

The theoretical and experimental studies of the cumulative effects on refractive index modification dynamics during filamentation from femtosecond light pulses in transparent media are presented. Residual changes of the refractive index were shown as developing both in forward and backward directions forming prolonged tracks of modified index profiles (waveguides) during repetitious laser shots.

Direct SEM examination reveals a complex nanoscale structure of deep narrow central channels within shallow wide external craters produced by single-shot high-intensity femtosecond laser radiation on Corning 0211 glass and sapphire surfaces. These internal narrow channels are not expected from ordinary surface melt spallation and expulsion processes characteristic of the external surface nanocraters, but exhibit nearly the same appearance threshold. Surprisingly, the nanochannel radiuses rapidly saturate versus incident laser intensity indicating bulk rather than surface character of laser energy deposition, in contrast to the external craters extending versus laser intensity in a regular manner. These facts may be explained by channeling of electromagnetic radiation by near-surface ablative filamentary propagation of intense femtosecond laser pulses in the highly electronically excited dielectrics, by spherical aberrations in the surface layer, or deep drilling of the samples by short-wavelength Bremsstrahlung radiation of relatively hot surface electron-hole or electron-ion plasma. The double structure of ablated surface nano-features is consistent with similar structures observed for bulk damage features fabricated by femtosecond laser pulses at supercritical laser powers, but much lower laser intensities.

The supercontinuum conical emission of a 50-fs laser pulse focused into a Κ 108 glass is studied experimentally and numerically. It is found that, as the pulse energy was increased from 2 to 30 uj, the continuous picture of conical emission decomposed into speckles upon focusing with a lens and split into narrow rings upon focusing with an axicon. Preserving of distinct interference picture under more than 1000 shots exposure evidences in favor of much more stable positioning of microfilament in the case of axicon.

Filamentation, which arises in the propagation of ultrashort laser pulses when the defocusing on the generated plasma dynamically balances the Kerr self-focusing, is now well described on both the laboratory scale (millijoules to tens of millijoules, meters to tens of meters) and the atmospheric scale (hundreds of millijoules, hundreds of meters to kilometers). The scalability of this propagation regime to higher energies and powers is not a priori assured, as high-order nonlinear effects may prevent long distance propagation leading, for instance, to full beam collapse. We thus investigated the atmospheric propagation of the 26 J, 32 TW laser pulses delivered by the Alisé beamline, which exceed respectively by one and two orders of magnitude the characteristic power and energy of ultrashort pulses studied so far. We show that filamentation still occurs at these extreme levels. More than 400 filaments simultaneously generate a supercontinuum propagating up to the stratosphere, beyond 20 km. This constitutes the highest power "white-light laser" to date. We also discuss the results of another experiment realized with the Teramobile laser facility: we demonstrated optimal control on the propagation of ultrashort 5 TW laser pulses in air over distances up to 36 m in a closed-loop scheme. We optimized three spectral ranges within the white-light continuum, as well as the ionization efficiency. Optimization results in signal enhancements by typical factors of 2 and 1.4 for the target parameters. In the case of white-light continuum generation, the feedback-driven procedure leads to shorter pulses by reducing their chirp, while, as far as air ionization is concerned, the optimization consists in correcting the pulse from its defects and setting the filamentation onset near the detector.

The initiation and propagation of a filament generated by ultrashort laser pulses in both fog and turbulent air is investigated experimentally. Filaments can propagate through dense fog, supported by the surrounding photon bath, which is transmitted and re-feeds the filament after he diffracts on a water droplet. Filaments can can also be generated and propagated even after the beam has propagated through strongly turbulent regions, with structure parameters C_n² up to 5 orders of magnitude larger than encountered in usual atmospheric conditions. Moreover, the filament position within the beam is not affected by the interaction with a turbulent region. This remarkable stability is allowed by the strong Kerr refractive index gradients generated within the filament, which exceed the turbulence-induced refractive index gradients by 2 orders of magnitude.

Atmospheric turbulence influence on stochastic filamentation of the chirped femtosecond laser pulses in the kilometer-range propagation is analyzed. The problem of the chirped pulse parameters optimization is discussed. An effective semi-analytical method is suggested to investigate chirped pulse propagation and filamentation over kilometer range distances in the turbulent atmosphere.

The feasibility of a microwave waveguide made of plasma channels under laser pulse filamentation is discussed. The necessary channel bunch configuration is achieved by initial intensity modulation of a femtosecond pulse. Estimations are given for wavelength of the microwave radiation and for parameters of the plasma channels configuration.

Two-dimensional multicolored transverse arrays were generated in a quadratic nonlinear medium under the pump of two crossly overlapped femtosecond beams based on the cascaded non-collinear quadratic nonlinear couplings between the input pulses and quadratic spatial solitary waves originated from spatial breakup of one of the input beams with a small asymmetry. A probing supercontinuum pulse was diffracted and amplified with phase preservation, resulting in the formation of up-converted multicolor two-dimensional transverse arrays. By seeding with weak second harmonic pulses, the two-dimensional multicolored transverse patterns could be suppressed through weak beam control of the induced quadratic spatial solitary waves. At a high-intensity pump, colored conical emissions could be observed as a result of spatiotemporal collapse of femtosecond pulses in a quadratic medium. Seeded amplification of colored conical emission was demonstrated to support ultrabroadband up-conversion with a widely tunable range in wavelength and significantly high energy conversion efficiency.

This paper is devoted to the dynamics of attosecond pulses created during the high order harmonic generation process. In this goal we study Ti:sapphir laser pulses propagating in a H₂⁺ gas. The dynamics and propagation of the incident pulse is obtained by solving the macroscopic Maxwell equations. The molecular gas reaction on the electric field, the polarization, is derived from TDSE's following the model presented in [9], [10]. We are especially interested in this work, in the attosecond pulse dynamics and the intensity of the first harmonics dependently of the propagation length inside the gas, on the attosecond pulse generation and propagation and the energy of return graphs in function of the driver phase.

Focusing few-cycle pulses with duration 6 - 12 fs at 800 nm with moderate energy (0.25 - 0.35 mJ) into atmospheric pressure argon gives rise to filamentation (self-focusing) and a supercontinuum with a very broad pedestal, extending in the UV to 200 - 250 nm respectively. Apart from the very broad spectrum, this supercontinuum has other remarkable features as well, like absence of conical emission, no contribution from third harmonic, intrinsically shorter duration than the incoming pulse and spectral conversion efficiency that is on the level of 0.01 - 0.001. The application of the supercontinuum as a simple source of short UV pump pulses of tunable wavelength for transient spectroscopy is demonstrated.

The new method for determination of the filament onset distance of a high-power ultra short laser pulses in turbulent atmosphere is discussed. The results in a good agreement with outcomes of the slowly varying amplitude method.