Study On Ultrafast Nonlinear Optical Properties Of Pyrene Derivatives

Pyrene and its derivatives have many advantages such as strong two-photon absorption,ultrafast response speed and good light permeability.It can be used as two-photon fluorescence imaging,fluorescence probe,and can also be used as a potential optical limiting material in ultrafast field.In this paper,we investigate the nonlinear absorption properties of pyrene derivatives under nanosecond,picosecond and femtosecond pulse width by Z-scan method.The experimental results show that the samples have obvious reverse saturable absorption at different pulse widths.We use femtosecond PO pump probe technique to test the experimental samples,it is found that the pyrene derivatives have strong two-photon absorption,and the three order nonlinear mechanism is mainly due to two-photon absorption and two-photon excited state absorption.We investigate the nonlinear absorption properties of the samples in the wide wavelength range by using transient absorption spectroscopy and the femtosecond Z-scan,the experimental results show that the pyrene derivatives have excellent broad wavelength response,which makes it possible to be used as a wide band optical limiting material in ultrafast field.