title: Investigation of two-photon absorption induced excited state absorption in a fluorenyl-based chromophore.
abstract: Two-photon absorption induced excited state absorption in the solution of a new fluorenyl-based chromophore is investigated by a time-resolved pump-probe technique using femtosecond pulses. With the help of an additional femtosecond open-aperture Z-scan technique, numerical simulations based on a three-energy level model are used to interpret the experimental results, and we determine the nonlinear optical parameters of this new chromophore uniquely. Large two-photon absorption cross section and excited state absorption cross section for singlet excited state are obtained, indicating a good candidate for optical limiting devices. Moreover, the influence of two-beam coupling induced energy transfer in neat N,N'-dimethylformamide solvent is also considered, although this effect is strongly restrained by the instantaneous two-photon absorption.
authors.affiliation: Department of Physics, Harbin Institute of Technology, Harbin 150001, PR China.
authors.forename: Changwei
authors.initials: C
authors.lastname: Li
authors.forename: Kun
authors.initials: K
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: Xinyan
authors.initials: X
authors.lastname: Su
authors.forename: Junyi
authors.initials: J
authors.lastname: Yang
authors.forename: Xiao
authors.initials: X
authors.lastname: Jin
authors.forename: Min
authors.initials: M
authors.lastname: Shui
authors.forename: Yuxiao
authors.initials: Y
authors.lastname: Wang
authors.forename: Xueru
authors.initials: X
authors.lastname: Zhang
authors.forename: Yinglin
authors.initials: Y
authors.lastname: Song
authors.forename: Hongyao
authors.initials: H
authors.lastname: Xu