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The results of in vivo optical immersion clearing of human skin under the effect of aqueous solutions of some immersion agents (monosaccharides of ribose, glucose and fructose, as well as glycerol, a triatomic alcohol) were obtained with the use of the OCT method. Values of average velocity of scattering coefficient change, obtained through an averaged Ascan of the OCT signal in the region of derma with the depth of 350 to 700 µm, were determined to evaluate the optical clearing efficiency. The velocity of scattering coefficient change and the optical clearing potential value appeared to be well correlated. The complex molecular modeling of a number of immersion clearing agents with a mimetic peptide of collagen (GPH)3, carried out with the use of the methods of classical molecular dynamics and quantum chemistry, allowed to identify correlations between the optical clearing efficiency and such a property as the energy of intermolecular interaction of clearing agents with a collagen peptide fragment.

We demonstrate the feasibility of the proposed new approach to CARS thermometry of hydrogen-containing mixtures with simultaneous measurement of the intensities of a hydrogen spectrum Q-branch lines and their linewidths in a single laser shot by means of a spectrograph combined with an interferometer, that have orthogonal directions of dispersions. This provides correct temperature evaluation that takes into account the linewidths, measured directly. The experiments were carried out in a H 2 :N 2 = 1:10 mixture in a heated cell at a temperature of 1050 K. The values of gas mixture temperature, that were defined in a pressure range of 2-9 MPa from DBB CARS spectra taking into account linewidth corrections, coincide with a thermocouple measurements within ~ 2 %. Without these corrections the discrepancies increase up to 5 %. The proposed approach can be applied to CARS thermometry in the course of investigations of H 2 and hydrocarbon combustion without the necessity to measure species concentrations, and does not require the knowledge of the line-broadening coefficients.

We report on ultra-high catalytic activity of metallic structures consisting of densely packed assemblies of nano-size metallic (Cu) granules. These nanostructures are fabricated by a new method of laser electrodispersion. The major results on experimental studies of catalytic activity of Cu nanostructures are presented by the example of dichlorobutene isomerization. The observed high catalytic activity of granulated Cu nanostructure is explained by the presence of charges appeared at the granules due to thermally activated inter-granule electron tunneling. The charge state of the structure is analyzed by using newly developed Monte-Carlo model.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The possibility is considered of restoring the electron energy distribution function (EEDF) in the interval of electron energies 0 < e < 5 eV from measurements of translational and vibrational temperatures by the coherent anti-Stokes Raman scattering (CARS) method in a positive column of a glow discharge in molecular nitrogen at 20

Diagnostics of gas mixtures with fluctuating temperature, density and concentration composition requires simultaneous detection of spectra of all species of a mixture with subsequent its joint treatment. Strategy of processing of experimental data, obtained at diagnostics by methods of a spectroscopy of Coherent Anti-Stokes Raman Scattering, is considered. An experimental approach to a performance of density numbers measurements in three-component mixture of O2, H2, H2O in a flame of oxygen-hydrogen burner is presented.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The single shot autocorrelator designed to measure the AF of the ultrashort laser pulses in the temporal range of 30 - 200 fs and in spectral range 730 - 820 nm is described.

Dual-broadband coherent anti-Stokes Raman spectroscopy (CARS) of the Q-branch of H2 has been employed for thermometry in a laboratory atmospheric pressure hydrogen-oxygen flame. The aim was to investigate the applicability of the technique for single-shot temperature evaluation, to estimate its sensitivity and to analyze the accuracy of the measurements. The results are presented of single-shot temperature mapping of the flame in the temperature range of 700 - 3200 K. The achieved accuracy of single-shot measurements was 3 - 5%.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The stable form of the pulse train is naturally reproduced in ultrashort-pulse lasers with low amplification in the active media. In lasers with a high amplification factor per pass an instability of train structure is observed with stable full output energy of radiation. The paths for stabilization of train structure by the use of regenerative amplification or stabilization of amplification of an active media with accuracy of 0.5 percent are offered.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Laser driven gas-phase synthesis in a flow reactor was employed for the production of carbon and silicon cluster beams starting from gaseous compounds. It is based on a CO 2 -laser-induced decomposition of molecular gases containing carbon and silicon, such as C 2 H 2 and SiH4. By introducing a skimmer into the reaction zone, the generated clusters are transferred to the free molecular flow and analyzed with a time-of-flight mass spectrometer. The carbon clusters are characterized by a bimodal distribution. In the region of lower masses C(subscript n clusters were observed up to n equals 19 with the progression n equals 1. In the higher mass fullerenes were observed C 60 and C 70 . Also observed were two types of silicon: clusters with number of atoms up to 12 and also large ones with number of atoms 700 - 1000 which corresponds to nanometer-size. These clusters were deposited on a silicon or sapphire target at room temperature. Micro-Raman spectroscopy techniques were used for characterization of these deposits. In particular for silicon two features in the Raman spectrum were evident: one broad band and a sharp peak which correspondently were attributed to silicon amorphous and crystalline phase and that nanocrystallites deposited on the substrate consist of about 800 atoms (quantum dots with a size of about 3 nm). Thus, the present studies show that the laser-driven nucleation in a flow reactor is a powerful technique to produce fullerenes and silicon quantum dots and other nano- size semiconductors or high-temperature evaporated materials.

A tunable KTP optical parametric oscillator (OPO) operating on a single longitudinal mode of its resonator is described. Single mode operation has been achieved by using an intracavity Fabry-Perot etalon in a short-length OPO resonator. The crystal is pumped by the second harmonic of a 10 Hz, Q-switched, injection-seeded Nd:YAG laser. the tuning range observed with a crystal cut at 60 degrees is 0.75 - 0.87 micrometer for the signal beam and 1.83 - 1.37 micrometer for the idler beam. The linewidth of the OPO is 200 MHz (0.0066 cm -1 ), which is very close to the Fourier limit. The total output energy (signal plus idler) was measured to be up to 0.6 mJ per pulse at a pump energy of 10 mJ.

In this work we present the results of two-wavelength rotational CARS thermometry (2(lambda) -CARS thermometry) of hydrogen at temperatures from 300 K to 1100 K. Experimentally, temperature was measured in a heated cell using single-shot and averaged CARS intensities in the rotational S-branch. Relative standard deviation for single-shot temperature values was approximately 1.5% at 296 K and approximately 8% at 1000 K. The accuracy achieved, its dependence on measured temperature, and possibility of their improvement were analyzed.

In the course of the clinical trials of Photosens (Al-sulphonated phthalocyanine) as a drug for PDT of cancer fluorescence examinations of 45 patients with injected photosensitizer (0.5 - 2.0 mg/kg b.w.) were performed. The aim of these investigations was to study the drug accumulation in normal, inflammatory tissues and tumors of different localizations. The data concerning kinetics of photosensitizer accumulation and its removal from normal skin and lip mucosa are also presented.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Photosensitizer Photosens is a mixture of sulphonated Al-phthalocyanines with a different number of substituents per phthalocyanine molecule. In the beginning of 1994, this photosensitizer was approved for clinical trials. Since that time till May 1995, 45 patients with 120 tumors were treated by PDT-Photosens. The main tumor localizations were lung (5/6), head and neck (4/4), esophagus (8/8), stomach (2/2), vulva (2/2), bladder (1/1), breast cancer (3/3), skin (basalioma, melanoma, sarcoma Kaposi, mts breast cancer) (20 patients/94 tumors). The lesions were photoirradiated 48-72 h after intravenous injection of Photosens in doses from 0.5 to 2.0 mg/kg b.w. (1.0 mg/kg b.w., on average). PDT was performed by laser power density from 20 to 1400 mW/sq cm (300 mW/sq.cm, on average), energy density varying from 15 to 200 J/sq cm (100 J/sq.cm, on average). The therapeutical effect of PDT was evaluated histologically, endoscopically, roentgenologically and sonographically 3 - 4 weeks after the treatment. Complete regression of tumors was reached in 56%, significant remission was reached in 34%, and partial remission was observed in 10% of cases. The follow-up of patients with complete tumor regression was to 15 months.

In this paper the results of fluorescence diagnostics and photodynamic therapy of early stage malignancies of lung (17 patients) and esophagus (8 patients) are presented. 13 patients had multiple primary tumors. As photosensitizers the new drugs Photoheme and Photosense were used. Complete remission was obtained in 92%. The patients are followed up without relapses to 2,5 years.

Raman studies of Si layers prepared on c-Si and Al 2 O 3 substrates at 300 K by well defined cluster beams have been carried out to establish correlation between the cluster species and the layer composition. The Si clusters were generated by a carbon-dioxide-laser-induced decomposition of SiH 4 in a flow reactor and were transferred to a free molecular flow by introducing a skimmer into the reaction zone. A mass spectroscopic analysis shows that this source emits two qualitatively different types of clusters: small clusters consisting of up to 12 atoms and large species of nearly 10 3 atoms. To produce the Si layers the substrate was placed perpendicular to the cluster beam. The Raman spectra of the deposited clusters show a broad amorphous-like band and a relatively sharp peak at 518.1 cm -1 . Analysis of the Raman shift and line width of this peak based on phonon confinement models allows us to conclude that this peak corresponds to nanocrystals with a size of about 3 nm. This size corresponds to the number of atoms in the large clusters of the cluster beam. It means that the layers conserve the specific properties of the large incident free clusters.

In the course of clinical trials of Photosens (Al-sulphonated phthalocyanine) as a new drug for PDT of cancer fluorescence observations of patients with injected photosensitizer are performed. The aim of current investigations is to develop the clinical method of cancer diagnostics with Photosens, to study the pharmaco-kinetics of the drug in the human body and its retention in tumors.

The first clinical trials of photodynamic therapy (PDT) in Russia were started in P. A. Hertzen Moscow Research Oncology Institute in October of 1992. Up to now, 61 patients with primary or recurrent malignant tumors of the larynx (3), trachea (1), bronchus (11), nose (1), mouth (3), esophagus (12), vagina and uterine cervix (3), bladder (2), skin (6), and cutaneous and subcutaneous metastases of breast cancer and melanomas (6) have been treated by PDT with the photosensitizer Photogem. At least partial tumor response was observed in all of the cases, but complete remission indicating no evident tumors has been reached in 51% of the cases. Among 29 patients with early and first stage cancer 14 patients had multifocal tumors. Complete remission of tumors in this group reached 86%.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A compact experimental spectrometric system designed for experimental and clinical fluorescence diagnostic observations of tumors is described. Methods of tumor diagnostics using fluorescence spectra of photosensitizers employed for photodynamic therapy has been developed. The system has been tested in P.A. Hertzen Moscow Research Oncology Institute for direct and endoscopic fluorescence diagnostics of tumors in the course of clinical trials of new domestically produced drugs.