Influence of BaTiO3 particles on second harmonic generation in liquid crystal 5CB

Second harmonic generation (SHG) in the colloid based on barium titanate particles and the liquid crystal (LC) 4-cyano-4'-pentylbiphenyl (5CB) was detected. Furthermore, the SHG signal from the 5CB + BaTiO3 colloid was observed at lower power of exciting radiation than in the pure 5CB. It is shown that the SHG intensity has the maximum value at polarization of exciting radiation along the preferred direction of LC molecules. In this case, it depends on the value of the applied electric field. Experimental results were explained by the photo-stimulated polarization of ferroelectric particles and orientation of LC molecules, formation of local electric field around these particles and also momentary symmetry of the system at action of short laser impulses.