Studies Organic Polymeric Materials DSB & TSB Of Two-photon Absorption And Time-resolved Fluorescence Spectrum

In this thesis,we construct the two-photon absorption cross section and time-resolved fluorescence spectrum measurment technology by fs laser as the pump laser and monochromator,CCD,ICCD as the detect system.We used two-photon absorption excitation and Z-Scan technology measurment the new organic polymeric materials'1,4-di(4'-N,N-diphenylaminostyryl)benzene(DSB) and 2,5,2',5'-tetra (4'-N,N-diphenylaminostyryl)biphenyl(TSB)'s TPA cross sections,which have D-Ï€-D structure,large TPA cross section,strong TPA fluorescence and high fluorescence quantum efficiency.We also measurement the two materials's time-resolved fluorescence spectrum ,from the spectrum we get the lifetime of fluorescence.In the measurement of two-photon absorption excitation ,from the linear absorption of the two materials,we think in the wavelength of 600nm-1200nm may be exist two-photon absorption.So we use 600nm-800nm fs laser pump the samples to get the TPA fluorescence.when we use 745nm wavelength pump the DSB and TSB ,we get the maximum TPA cross section are 927GM and 3288GM.In the same concentration ,TSB have two times conjugate chain as long as DSB,but the TSB have nearly four tmes TPA cross section as large as DSB.The reasons are that: one is the TSB's conjugate chain is longer than DSB;the other is TSB's three dimension Twist link is cover the bipheny chromospheres. For affirm the result ,we also use the Z-Scan technology to measurement the TPA cross section, when we use 800nm wavelength pump the samples, we get the two materials'TPA cross section are 242GM and 430GM.They are fit the values of use two-photon absorption excitation at 800nm well.So we know the two materials are have large TPA crosss section,they all have the protein be used in frequence upconversion laser,optical limited,three dimension optical storage,two-photon fluorescence images and so on.From the two materials time-resolved fluorescence spectrum ,we get the two materials'lifetime of fluorescence and the components .We know they all have two componenets ,the short fluorescence lifetime areall less than 1ns,the long fluorescence lifetime are nearly 35ns and 20ns.It demonstrate that they all have singlet and triplet energy structure.Then we change the pump energy, we get the rule of the fluorescence curve top value change.