Han Yanbing, Xiao Jinchong, Wu Xingzhi, Wang Yuxiao, Zhang Xueru, Song Yinglin
Department of Physics, Harbin Institute of Technology, Harbin 150001, China.
Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China.
Molecules. 2022 Jun 1;27(11):3564. doi: 10.3390/molecules27113564.
A novel two-branched twistacene () has been designed and synthesized for application on ultrafast optical limiting. This twistacene exhibits excellent two photon absorption and two photon absorption-induced excited singlet state absorption, which was systematically investigated with a femtosecond Z-scan experiment, transient absorption spectrum, and two-photon excited fluorescence experiments. The admirable two photon absorption is attributed to the high degree of π electron delocalization in twistacene which is caused by introduction of two strong donors. The excited singlet state absorption cooperates with two-photon absorption to provide an excellent ultrafast optical limiting behavior with high linear transmittance, where the thresholds are 2.3-5.3 mJ/cm in the spectral region of 532-800 nm of femtosecond laser and 133 mJ/cm for picosecond pulse at 532 nm. These thresholds are lower than that of most of the optical limiters reported previously, which indicates is a promising candidate for ultrafast optical limiting.
一种新型的两分支并四苯（）已被设计并合成用于超快光学限幅应用。这种并四苯表现出优异的双光子吸收和双光子吸收诱导的激发单重态吸收，通过飞秒Z扫描实验、瞬态吸收光谱和双光子激发荧光实验对其进行了系统研究。令人钦佩的双光子吸收归因于并四苯中由引入两个强供体导致的高度π电子离域。激发单重态吸收与双光子吸收协同作用，以提供具有高线性透过率的优异超快光学限幅行为，其中在飞秒激光532 - 800 nm光谱区域的阈值为2.3 - 5.3 mJ/cm²，在532 nm处皮秒脉冲的阈值为133 mJ/cm²。这些阈值低于先前报道的大多数光学限幅器的阈值，这表明是超快光学限幅的一个有前途的候选者。
