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Information × Registration Number 0308U001665, 0106U003117 , R & D reports Title Nonlinear optical properties and spectroscopy of photosensitive and complex dielectrical thin-films' systems popup.stage_title Дифракційні та спектроскопічні дослідження світлочутливих плівок Head Ageev Leonid Opanasovich; Milislavsky Volodimir Kostyantinovich, Registration Date 15-02-2008 Organization Kharkov Natuional university named after V.N.Karazin popup.description2 Object of examinations - thin light-sensitive films with a real time sensitivity; quasi-unidimensional dielectric with impurities. The aim of work - study of nonlinear optical effects in photosensitive films and exciton spectra of quasi-unidimensional crystals with various impurities. Methods of investigation - vacuum preparation of films, film irradiation by monochromatic light, spectroscopic and diffraction measurements, microscopic examinations of the film morphology and structure. Mechanisms of competition of waveguide TE0- and TM0-modes in AgCl-Ag films at spontaneous grating development were studied on the basis of existent theories. First mechanism describes evolution of TE0- and TM0-gratings using the Lottki-Volterra equations. It is relevant at small laser beam incidence angles ?. Second mechanism is based on two-dimensional Bragg diffraction of modes on specified gratings. It is relevant at large incidence angles. A new scheme is proposed to conduct self-diffraction observations and to form two-dimensional gratings in As2S3-Ag films. A method of laser implantation of nanoscaled Ag particles into amorphous quartz is proposed. Size of the particles (6 nm) in quartz surface layer is determined by means of electron microscopy and atomic force microscopy. Spectral measurements have shown that the colloidal band has Lorenz form and that it is located at the Frolich frequency. Absorption spectra of thin films of solid solutions (MI)1-y(Ag1-xCuxІ)y (M=К,Rb,Cs) at specified outlet molar concentration у=0.33 were studied. It is ascertained that at small molar concentrations х a local exciton band chips off the main long-wave exciton bands. The local exciton band is associated with Cu+ ions. Concentrational shift of exciton bands indicates creation of stable-type exciton spectrum. However in Rb2Ag1-xCuxІ3 at х і 0.5 and in Cs2Ag1-xCuxІ3 at х > 0.2 exciton spectra of mixed type are formed. They are associated with creation of more stable solid M3Ag2-2xCu2xІ5 solutions. Spectra of plasma resonance in granularfilms of Ag-In alloys have been studied and interpreted. Results of the research are used for further development of nonlinear optics of thin films, for development of the theory of local excitons in quasi-unidimensional crystals. The forecast assumptions on further development of test subject - further extended study of nature and mechanisms of unusual optical phenomena in various thin films. Product Description popup.authors popup.nrat_date 2020-04-02 Close