Degenerate nonlinear absorption and optical power limiting properties of asymmetrically substituted stilbenoid chromophoresElectronic supplementary information (ESI) available: Experimental details. See http://www.rsc.org/suppdata/jm/b3/b313185h/
作者:Tzu-Chau Lin、Guang S. He、Paras N. Prasad、Loon-Seng Tan
DOI:10.1039/b313185h
日期:——
Two-photon absorption (2PA) spectra (650–1000 nm) of a series of model chromophores were measured via a newly developed nonlinear absorption spectral technique based on a single and powerful femtosecond white-light continuum beam. The experimental results suggested that when either an electron-donor or an electron-acceptor was attached to a trans-stilbene at a para-position, an enhancement in molecular two-photon absorptivity was observed in both cases, particularly in the 650–800 nm region. However, the push–pull chromophores with both the donor and acceptor groups showed larger overall two-photon absorption cross-sections within the studied spectral region as compared to their mono-substituted analogues. The combined results of the solvent effect and the 1H-NMR studies indicated that stronger acceptors produce a more efficient intramolecular charge transfer character upon excitation, leading to increased molecular two-photon responses in this model-compound set. A fairly good 2PA based optical power limiting behavior from one of the model chromophores is also demonstrated.
通过一种基于单个强飞秒白光连续波束的新型非线性吸收光谱技术,测定了系列模型染料在650-1000 nm范围内的双光子吸收(2PA)光谱。实验结果表明,当电子供体或电子受体分别连接到反式-均二苯代乙烯的邻位时,两种情况下都观察到分子双光子吸收性的增强,尤其是在650-800 nm区域。然而,与单取代的类似物相比,同时含有供体和受体基团的推-拉型染料在整个研究光谱范围内表现出更大的双光子吸收截面。溶剂效应和1H-NMR研究的联合结果表明,更强的受体在激发时产生更有效的分子内电荷转移特性,导致该模型化合物系列中的分子双光子响应增强。其中一种模型染料的相当好的2PA基光学功率限制行为也被展示。