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Information × Registration Number 0218U001234, 0113U001667 , R & D reports Title Nonstationary sizedependant optical processes in nanostructured materials. popup.stage_title Head Blonskyy I.V., Registration Date 26-01-2018 Organization Institute of physics NASU popup.description2 The objects of the study are femtosecond filaments, conical emission, femtosecond supercontinuum, chalcogenide glass ceramics, quartz, sapphire, nanocluster phases and nanoparticles of binary semiconductors. The aim of the work is the study of the dynamics of the structure of the electromagnetic field, plasma and matter in the interaction of ultrashort laser pulses with solid-state Kerr media; the study of laser-induced non-stationary and dimensionally dependent optical processes. The research methods are femtosecond time-resolved optical polarimetry, time-resolved kinetics of induced light absorption, spectroscopy of secondary emission of light, electron microscopic methods of surface diagnostics, mathematical modeling. The methodology of precision time-resolved investigations of the kinetics of optical and induced optical properties of optical structural and nanostructured materials in the femto-, picosecond time interval is developed by taking into account the influence of the "chirp" of the supercontinuum pulse - different time delays of its various spectral components, "cross phase modulation" - action of the "pump" pulse on the frequency of the "probe" one, taking into account the influence of the group velocity dispersion within the spectral-expanded pulse. New techniques are developed: a femtosecond time-resolved microscope for the study of filamentation processes and single-pulsed laser ablation and the "Kerr gate" for the study of luminescence kinetics with a resolution of 300 fsec. The conditions of "attractive" and "repulsive" interactions of two filaments in transparent isotropic solid-state environments are established. The phenomenon of time auto-localization of femtosecond pulses was discovered and investigated, which allowed to shorten their duration from 160 fs to 65 fs. For the first time, the phenomenon of periodic femtosecond filamentation in environments with a positive (quartz) and negative (sapphire) birefringence was discovered and it was proved that its cause is the cyclic transformation of the state of the polarization of the light pulse, due to the onset of phase difference between ordinary (o) and extraordinary (e) rays. The polarization features of supercontinuum and conical emission in birefringent refracting media are observed for the first time, which are explained by the time difference of the o- and e-rays. For non-transparent targets, the kinetics of single-pulse laser ablation of the stages of formation of a plasma torch, the formation and thermalization of the plasma, the exclusion of the material, and the formation of an ultrasonic shock wave are investigated. Correlation between the orientation of the lattice graves on the surface of refractory metals, which are formed under the influence of one-beam irradiation by femtosecond laser pulses, the direction of polarization and the direction of scanning of the laser beam are found. It was found that during long-term irradiation of Au colloidal nanoparticles by femtosecond laser pulses there is a transformation of their initial cylindrical shape into spheroidal, which is visually manifested in the color change of colloid. On the basis of the quantum-chemical calculations of the nested shell structures of (ZnO)n clusters, the conclusion was drawn about the nature of the formation of "magic clusters" of this compound, which is genetically related to the deformation of the structure due to Jahn-Teller symmetry reduction, that paves the way for the growth of tetrapods. On the basis of the researches of femtosecond laser ablation of chalcogenide glass-like semiconductors, economically attractive femtosecond express technologies for creating of the arrays of elements of micro-optics are proposed, which are promising for optoelectronic and telecommunication uses. Product Description popup.authors Блонський Іван Васильович Головченко Олена Миколаївна Дмитрук Ігор Миколайович Дмитрук Андрій Миколайович Зубрілін Микола Глібович Кадан Віктор Миколайович Коренюк Петро Іванович Павлов Ігор Анатолійович Павлова Світлана Володимирівна Рибак Андрій Станіславович Шенделєва Маргарита Леонідівна Шинкаренко Євген Вікторович Ярусевич Олександр Олексійович popup.nrat_date 2020-04-02 Close