中文摘要：

用飞秒Ti∶sapphire激光研究了3个树枝分子1,2,4,5-四（4-N,N-二苯氨基苯乙烯基）苯（TPAB）、1,2,4,5-四[4-N,N-二（4-溴苯基）氨基苯乙烯基]苯（TPAB-Br）和1,2,4,5-四{4-{N,N-双{4-{4-[5-（4-叔丁基苯基）-1,3,4-噁二唑-2]苯乙烯基}苯基}氨基}苯乙烯基}苯（TPAB-OXA）的多光子吸收及上转换荧光性质.在二氯甲烷溶液中3个生色团分子TPAB,TPAB-Br和TPAB-OXA在800 nm飞秒光激发的双光子荧光发射波长分别为569,535和621 nm,在1300 nm飞秒光激发的三光子频率上转换荧光发射波长分别为566,534和610 nm,采用非线性透过率法测得在四氢呋喃（THF）溶液中TPAB,TPAB-Br和TPAB-OXA在800 nm和150fs激光激发下双光子吸收截面分别为61.86×10-50,6.19×10-50和65.98×10-50 cm4.s/photon;在1300 nm和80 fs激光激发下三光子吸收截面分别为3.88×10-79,7.76×10-79和27.17×10-79 cm6.s2.树枝分子具有很强的多光子吸收和上转换荧光发射能力,多光子荧光发射波长位于500～600 nm.

英文摘要：

The multiphoton absorption and multi-photon-excited upconversion fluorescence of dendrimers,1,2,4,5-tetra（4-N,N-diphenylaminostyryl） benzene（TPAB）,1,2,4,5-tetra[4-N,N-di（4-bromophenyl） aminostyryl]benzene（TPAB-Br） and 1,2,4,5-tetra{ 4-{ N,N-bis{ 4-{ 4-[5-（4-tert-butylphenyl）-1,3,4-ox-adiazol-2-yl]styryl} phenyl} amino styryl} benzene（TPAB-OXA）,were measured by a femtosecond Ti∶ sap-phire laser.The absorption,fluorescence emission and fluorescence lifetime of these octupolar chromophores were investigated.Pumped by a femtosecond laser at 1300 nm and 800 nm,strong upconversion fluorescence were observed.The maximum peaks of two-photon fluorescence in the solution of CH2Cl2 are at 569 nm for TPAB,at 535 nm for TPAB-Br and at 621 nm for TPAB-OXA,respectively.The three-photon excited fluores-cence with the central wavelength at 566 nm for TPAB,at 534 nm for TPAB-Br and at 610 nm for TPAB-OXA in the solution of CH2Cl2 were observed.The two-photon absorption cross-section of chromophores obtained by nonlinear transmission method was 61.86 × 10-50 cm4.s/photon for TPAB and 65.98 × 10-50 cm4.s/photon for TPAB-OXA in the solution of THF.Large optical power limiting was demonstrated for the octupolar chro-mophores.Their three-photon absorption coefficients of 1300 nm in THF were 3.88 × 10-79,7.76 × 10-79 and 27.17 × 10-79 cm6.s2,respectively.The dendrimers displayed large multi-photon absorption and strong upconversion fluorescence properties.