Influence of corona poling procedures on linear and non-linear optical properties of polymer materials containing indandione derivativatives as a cromophores

SHG efficiency of the poled guest - host polymer system is proportional to the concentration and orientation degree of NLO active molecules (chromophores). Corona poling realized at elevated temperatures could cause concentration decrease of NLO- active molecules due to centrosymmetric crystallization. Our studies showed that number density of crystallites is depending on orientation procedure. To obtain the best orientation procedure for guest - host systems containing four different chromophores based on dimethylaminobenzylidene 1, 3 - indandione we have compared optical images and SHG efficiency of corona poled films. According to our observations external poling electric field applied from the very beginning of the sample heating process can reduce crystallite grow. The optical quality is improved and SHG efficiency in some cases is up to 1.6 (depending on molecule structure) times larger after our suggested orientation sequence compared to classic corona poling procedures.