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Information × Registration Number 0218U002729, 0115U004249 , R & D reports Title Atomic, molecular and nanoscale structures in gradient laser fields: mechanisms of formation, optical and laser properties, application in spectroscopy, laser technology and sensorics. popup.stage_title Head Yatsenko Leonid Petrovich, Registration Date 30-05-2018 Organization Institute of physics NASU popup.description2 The object of study - atoms, molecules and nanoparticles in the light field; developed by the authors a light-sensitive photopolymer composite that allows the production of periodic structures of polymer-nanoparticles (LF) of silver by holographic lithography. Purpose - study of the motion of atoms, molecules and nanoparticles in the field of opposing waves. Investigation of the influence of structuring of polymer nanocomposite with nanoparticles of silver on their nonlinear properties. Research methods - analysis of processes of resonance interaction of laser radiation with atoms and molecules by means of modeling of wave function by the Monte Carlo method and density matrix. Description of the mechanical motion of atoms and molecules using the Newton equations. Application of the Monte Carlo method for computing the statistical characteristics of an ensemble of atoms. The nonlinear-optical characteristics of the structures based on the polymer nanocomposite with LF silver were measured by the Z-scanning method. Results - Investigation of the behavior of atoms in the field of counter frequency-modulated light waves, one of which repeats another, revealed, depending on the parameters of interaction with the field, a large variety of their motion. So, it is possible 1) grouping of particles at a speed near its zero value; 2) grouping of particles at a speed near its non-zero value (or non-zero values) along the direction of propagation of laser beams; 3) the trapping of particles by a field near a certain plane orthogonal to the front of the light waves, and the atomic velocity distribution can be characterized by a certain temperature (above the Doppler limit) or the concept of temperature can not be introduced (the atoms move at a certain direction and then instantly change it to the opposite); 4) it is possible the subdoppler cooling of atoms with their accumulation at the wave node. In addition, atoms form a one-dimensional, half-wavelength period, distribution in space. The obtained results can be extrapolated to the case of the motion of molecules or nanoparticles in the field of frequency-modulated radiation, if the interaction of the nanoparticle with the field is reduced to the interaction of the "active" atoms in the field with it, provided that such interaction can be described by a two-level scheme. As a result of the investigation of nonlinear-optical characteristics of a nanocomposite with chaotic and periodic distribution of silver nanoparticles, it was found that in nanosecond and femtosecond excitation, the values of nonlinear characteristics of ordered structures exceed the values obtained for disordered structures. The magnitudes of the nonlinear parameters of the investigated nanocomposite are not less, and in some cases one or two orders of magnitude exceed the values obtained by other authors. Complexes Kumarin 152A with silver nanoparticles and graphene oxide were created and characterized. Using SEM microscopy, Kumarin 152A, silver nanoparticles, recovered nano-flakes of graphene oxide and their complexes were characterized. The optical spectra of silver nanoparticles and silver nanoparticles with regenerated graphene oxide are registered. It has been shown that the complex of silver nanoparticles - recovered graphene oxide gives greater intensity of plasmon resonance than usual silver nanoparticles, indicating the promise of the complex for MEF and SERS experiments. Recovered graphene oxide has been characterized by Raman spectroscopy. The Raman spectrum of recovered graphene oxide had characteristic D and G peaks and a weak 2D peak. An enhanced luminescence (MEF effect) of the Kumarin 152A complex with silver nanoparticles and recovered graphene oxide has been obtained, which is approximately 67 times greate than the reference signal from Kumarin 152A. It should be noted that at points of enhanced luminescence, there was a bright directional luminosity, similar to filaments. At the same time, for this complex, an insignificant SERS effect was recorded that did not exceed 5 times. Product Description popup.authors Єжов Павло Валентинович Гринь Володимир Олександрович Кавелін Владислав Володимирович Лямец Олександр Костянтинович Мамута Олександр Дмитрович Романенко Віктор Іванович Смірнова Тетяна Миколаївна Фесенко Олена Мар'янівна Ходаковський Володимир Михайлович Яценко Леонід Петрович popup.nrat_date 2020-04-02 Close