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Information × Registration Number 0213U001371, 0112U004441 , R & D reports Title Studies of optical edge and defect modes and low threshold lasing in chiral liquid crystals. popup.stage_title Head Tichonov E.A., Registration Date 30-01-2013 Organization Institute of physics NASU popup.description2 Аn object of researches is - cholesteric liquid crystals, activated by organic dyes, a research purpose is - a study the effect of boundary conditions CLC director orientation on spectral, spatial and threshold characteristics of lasing, methods of researches and apparatus are - optical spectroscopy, including polarization, laser spectroscopy, theoretical and practical results - It is established that the relatively low thresholds of lasing on under optical pumping are implemented in the single-layer planar structures of cholesteric liquid crystals (CLC) with parallel directors on the substrate, however, are instituted in respect of a wide lasing spectrum in the three longitudinal modes. The spatial distribution of radiation when this is implemented in the form of a circular structure (Lagger-Gauss modes). In a similar texture CLC with perpendicular orientation of directors on the guiding substrate, which can lead to occurrence defect of "phase jump" type in the layer thickness there is a one-mode lasing in a wide range of pumping intensities and on the order of a smaller spectral width and angular divergence is reduced from 15 up to 2.5 degrees. In planar 2-layer texture of the impurity steroid CLC with the defect, created by the introduction in the middle of thickness the thin substrate, the mode spectrum of the lasing was the same as for the planar texture with a parallel orientation of directors. When higher threshold pumping intensity was applied lasing spectrum was expanded with synchronous growth of the angular divergence due to the excitement lasing in separate layers the 2-layer texture. Found that the spectral-angular characteristics of the lasing for induced CLC is not practically depend on the quality of the planar texture and thickness of the layer. Measured the threshold characteristics of the lasing in induced CLC at the variation of the angle between excitation beam and the director orientation of the liquid crystal on the substrate. It is established, that when you change the angle of excitement within 45 degrees from the direction of the spiral axis in the threshold increases that can be explained offset SR band regarding the maximum bandwidth of the dye amplification. Novelty - a practical novelty is the use of defective structures CLC to improve spectral and spatial characteristics of lasing, efficiency of application - not prove up to now, a sphere of future application finds in laser and optronic technique. Product Description popup.authors Ільчишин Ігор Павлович Микитюк Тарас Володимирович Тихонов Евген Олександрович popup.nrat_date 2020-04-02 Close