DAST@HP-β-CD超分子体系溶液的多光子泵浦激射

Multi-photon pump lasing of DAST@HP-β-CD supramolecular aqueous solution

激光的激射需要高浓度的增益介质,但增益介质浓度的过高又会带来浓度猝灭等不利因素,这些不利因素将会降低增益介质的发光效率。为解决这一矛盾,通过超分子策略,将有机非线性光学材料4-(4-二甲基氨基苯乙烯基)甲基吡啶对甲基苯磺酸盐(DAST)分子包覆于羟丙基-β-环糊精(HP-β-CD)分子的空腔中,并制备了DAST@HP-β-CD超分子水溶液。通过这种超分子包覆,可以大幅抑制DAST分子间的去活碰撞和分子内的Trans-Cis异构化,实现约6倍的荧光增强。不仅如此,在非线性光学效应方面,DAST@HP-β-CD超分子可通过多光子吸收而被激发。继而,以波长为1064 nm的纳秒脉冲激光泵浦超分子水溶液实现了二光子泵浦激射,激发阈值为平均功率620 mW。再者,以波长为1570 nm的非秒脉冲激光泵浦超分子水溶液,实现了三光子泵浦激射,激发阈值为峰值功率0.3 GW。在多光子荧光显微、三维信息存储等方面,超分子体系展示了良好的应用前景。

Lasing requires a high-concentration gain medium,but an excessive concentration of the gain medium will bring about unfavorable factors such as concentration quenching,which will decrease fluorescence efficiency of the gain medium in turn.In order to solve this contradiction,this paper proposes a supramolecular strategy,that is,including the organic nonlinear optical material 4-N,N-dimethylamino-4′-N′-methyl-stibazolium tosylate(DAST)molecule,by the cavity of hydroxypropyl-β-cyclodextrin(HP-β-CD)molecule,and DAST@HP-β-CD supramolecular aqueous solution was prepared.Through this kind of supramolecular structure,both the inactivation collision between DAST molecules and intramolecular trans-cis isomerization could be greatly suppressed,and we achieved the fluorescence enhancement by about 6 times.What’s more,the non-linear optical effects could also be enhanced.The DAST@HP-β-CD supramolecule could be excited by multi-photon absorption process.We achieved two-photon pumping lasing.This supramolecular aqueous solution was pumping with a 1064 nm nanosecond pulsed laser,whose excitation threshold was 620 mW(average power).Three-photon pumping lasing was accomplished.This supramolecular aqueous solution was pumping with a 1570 nm femtosecond pulsed laser,whose excitation threshold is 0.3GW(Peak power).which shows potential in multi-photon fluorescence microscopy and three-dimensional information storage.