两种新型芴类衍生物的三光子吸收特性研究

研究了两种新型芴类衍生物9，9_二（2_乙基已基）_2，7_二咔唑_9H_芴（简记为DCZF）和9 ，9_二（2_乙基已基）_2，7_二（2_（4_甲氧基）苯_2，1_乙烯基）芴（简记为BMOSF）在N ，N_二甲基甲酰胺（DMF）中的线性吸收和单光子荧光行为，并用脉冲宽度为38ps，重复 频率为10 Hz的1064 nm Nd：YAG脉冲激光研究了两种化合物的三光子吸收性质.结果表明： 两种新材料的最大线性吸收峰分别位于330和380nm，吸收区域覆盖了270—420 nm波段. 两种化合物的荧光带位于蓝_紫区，中心波长为369和442 nm，都具有较小的斯托克斯位移. 化合物DCZF和BMOSF的三光子吸收系数分别为γ_DCZF=678×10^{- 20} cm3/W²和γ_BMOSF=592×10^-20 cm³/W². 同时， 两种新材料还表现出明显的三光子吸收光限幅效应，当入射光强分别为8和6GW/cm²时，非线性透过率分别达到30%和45%. 关键词： 芴类衍生物 三光子吸收 光限幅 非线性透过率

Three-photon absorption properties of two novel fluorene-based derivatives

Two novel fluorene_based derivatives 9_(7_(9H_carbazol_9_yl)_9, 9_bis (2_ethylhexyl)_9H_fluorene_2_yl)_9H_carbazole (abbreviated as DCZF) and 2, 7_bis (4_metho xystyryl)_9, 9_bis (2_ethylhexyl)_9H_fluorene (abbreviated as BMOSF) were synthe sized and their linear absorption and one_photon fluorescence spectra were measu red. We used a 38ps, 1064nm Nd:YAG pulsed laser operating at 10 Hz to invest igate the three_photon absorption (3PA) properties of the two compounds. The re sults show that the linear absorption band of the two compounds is from 270—420 nm with absorption peaks at 330 and 380nm. The fluorescence bands were locat ed in the blue_violet region with the peak wavelengths of 369 and 442 nm, and s mall Stokes shifts were observed. Nonlinear absorption coefficients γ deriv ed from 3PA fitting curves are 678 and 592×10^-20 cm³/ W², respectively. Large optical power limiting induced by 3PA has also been demonstr ated for both dyes. When the incident irradiances reach 8 and 6 GW/cm^{2, t he limiting nonlinear transmissions of DCZF and BMOSF can reach to 30% and 45%, respectively.}