Hyper-Rayleigh scattering and multiphoton fluorescence of new merocyanine dye and stilbazolium salt

Abstract

The potential development of optoelectronic devices based on the nonlinear optical response of organic donor-acceptor molecules has aroused much recent interest. In this paper, two new ionic species in the classes of merocyanine dye and stilbazolium salt are studied by the newly developed Hyper-Rayleigh scattering (HRS) technique. Both compounds are dissolved in methanol under the 1064 nm-laser radiation in the experiments. The results show that the value of the first-order hyperpolarizability (beta) for the merocyanine dye is very large and for the stabilization salt is abnormally too large. Further studies reveal that both the merocyanine dye and the stabilization salt has multi-photon fluorescence (MPF) emission which overlaps the HRS signal at 532 nm under the radiation of 1064 nm but the merocyanine dye's MPF is weaker. If we cut off the MPF from the HRS signal, the (beta) value for the merocyanine dye is in the range of 10 -28 esu and the (beta) value for the stilbazolium salt is approximately equals 10 -27 esu, which is among the largest solution value of (beta) for organic species.