中文摘要：

强双光子吸收有机分子在激光光限幅领域具有重要应用价值。通过测量纳秒脉冲下输入/输出光强的变化、纳秒/飞秒抽运下分子的双光子吸收以及单光子荧光衰减曲线,研究了一系列含硫芴基的三苯胺衍生物对纳秒激光的限幅特性与机制。结果表明,分子激发态寿命与激光脉宽在同一量级有助于激发态再吸收;具有长激发态寿命的多枝形分子其激发态再吸收更明显、表观双光子吸收截面显著增大,有利于提高分子的激光限幅效率。

英文摘要：

Materials with large two-photon absorption（TPA） cross sections have the potential applications such as optical power limiting.Herein,the optical limiting of a series of multibranched chromophores based on triphenylamine is reported,and the comparative study of their two-photon absorption property pumped by 800 nm nanosecond and femtosecond laser pulses,associative with the fluorescence lifetime on the one-photon excitation,is performed.Results show that,with higher generation,multibranched molecules possess longer excited lifetime and stronger re-absorption on the excited state.Thus,the effective two-photon absorption cross-section pumped by nanosecond laser pulse is larger.As a result,larger optical limiting efficiency is obtained.