Study Of The Spatial Solitons In Carbon Nanotubes Doped Nematic Liquid Crystal

For spatial optical solitons research, nematic liquid crystal is the ideal material. It has been found that pure liquid crystal also exist shortcomings when observe the spatial optical solitons, in order to improve the pure liquid crystal, researchers found that the shortcomings would be eliminated when other materials was incorporated in the pure liquid crystals. The CNT(carbon nanotube)is a tubular structure with spiralization cycle, which is twisted from graphene sheet. There are a large number of unpaired electrons moving about around the tube wall. The carbon nanotube has both the conductivity of metal and the properties of semiconductor. There are helical angles in the CNT, which will be positive or negative, so the CNT has optical activity. In consideration of the good optical and electrical properties of the CNT, this paper will analyze and discuss the spatial optical solitons in the liquid crystal incorporating the CNT in both theory and experiment.In theory, we analyzed the factors influencing the reorientation angle of the nematic liquid crystals incorporating the CNT, so as to get the concrete expression of the angle since the molecular reorientation. Then according to the proper simplification and correction of the light wave evolution equation in the nematic liquid crystal, the equation of the spatial optical solitons in the liquid crystal incorporating the carbon nanotubes is deduced and the solution of the bright,dark solitons are gave, the width of the spatial optical solitons is computed. In addition, the light distribution of the optical soliton cross-section when parameters are different can be simulated according to above equations.In our experiments, we have prepared different concentrations of liquid crystal samples incorporating the CNT, as well as different thicknesses of liquid crystal cell (planar). We structured the optical path of the experiments, with the DPSS laser (532nm) as light source observe the forming process of spatial optical solitons and its variation when changing different factors, using CCD took all of the results of the experiment and comparing the spatial optical solitons of the experiments to the spatial optical solitons of the pure liquid crystal.Finally, for the influencing factors of the spatial optical solitons, we analyzed and compared from the thickness of liquid crystal cell, the power of incident light, the dosage concentration of carbon nanotubes, the applied voltage and the polarization orientation of incident light. We made detail analysis and conclusion to the properties of the spatial optical solitons in carbon nanotubes doped nematic liquid crystal.