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Information × Registration Number 0217U004830, 0115U003823 , R & D reports Title Influence of surface structure of orienting substrates on lasing characteristics of cholesteric liquid crystals. popup.stage_title Head Mykytiuk Taras Volodymyrovych, Registration Date 07-03-2017 Organization Institute of physics NASU popup.description2 Аn object of the researches are steroid cholesteric liquid crystals (CLC) that is a mixture of cholesterol esters which are activated by organic dyes, a research purpose is to study the spectroscopic and optical properties of the planar texture of such CLC formed by substrates of different types (quartz, Sital) at the same orientant, methods of researches and apparatus are optical spectroscopy, including polarization, laser spectroscopy, atomic force and scanning tunneling microscopy. Theoretical and practical results are: the studied transmittance spectra of steroid CLC showed a clear correlation between the type of used substrate and type of orientation of surface layer molecules on substrates. It was found that most qualitative orientation of planar texture is observed on Sital substrates at the perpendicular placement of the surface layers of molecules on substrates. Microscopic investigation of planar textures of investigated CLC found no difference in them. There is a large number of disclination while using all types of substrates and regardless of the type of orientation of surface layers of molecules on them. Lasing spectra of investigated CLC had the appearance of a longitudinal mode. It was found that the perpendicular orientation of the surface layers of molecules on substrates provides a lower lasing thresholds than at parallel orientation. Interrelation between spectrum and angular divergence of CLC laser can be formulated as follows: ring laser structure is associated with lasing of numerous longitudinal modes and disappears at single-mode generation that is not agreement with diffraction model of rings formation. Novelty - It was found that ring laser structure is associated with lasing of numerous longitudinal modes and disappears at single-mode generation that is not agreement with diffraction model of rings formation.. Product Description popup.authors Микитюк Тарас Володимирович Сененко Антон Ігорович popup.nrat_date 2020-04-02 Close