Abstract
Transient absorption saturation and degenerate four-wave mixing spectroscopies have been adopted to study nonlinear optical (NLO) properties of pseudoisocyanine (PIC) J-aggregates. In both the experiments, we find the inverted region where the NLO properties of J-aggregates decrease with the increase of the excitation density. To our knowledge, this inverted region is observed for the first time not only in J-aggregates but also in other materials. To study the peculiar phenomena, we observed NLO spectra of J band by using ultrafast white-continuum pump-probe experiments. Both results are discussed in terms of the coherent nonlinear processes and the exciton-phonon interaction in PIC J-aggregates.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
