Wavelength and intensity-dependent transient degenerate four-wave mixing in pseudoisocyanine J-aggregates
Wavelength and intensity-dependent transient degenerate four-wave mixing in pseudoisocyanine J-aggregates
复制标题
伪异花青 J 聚集体中波长和强度相关的瞬态简并四波混合
DOI：
10.1063/1.473899
复制
发表时间：
1997
影响因子：
4.4
通讯作者：
C. Rullière
中科院分区：
文献类型：
--
作者：
R. Gadonas;K. Feller;A. Pugžlys;G. Jonusauskas;J. Oberlé;C. Rullière
报道了氯化1，1 ′-二乙基-2，2 ′-花菁（pseudoisocyanine，PIC）聚集体在300 K下的瞬态简并四波混频（DFWM）和“泵浦-探测”光谱的研究结果。测量了J波段和激子共振附近DFWM效率的光谱色散。瞬态吸收变化和DFWM信号的时间响应被发现是强烈依赖于泵浦光子注量和波长。这种行为定性地解释内的非线性光学动力学的物理模型，占激子湮灭的聚集域，和非热声子产生的两个激子状态的衰减的结果的效果。在泵浦-探测实验中，由于非热声子引起的过量动力学无序的强度依赖性演化表现为在高泵浦强度下出现的色散型微分谱。在最高密度堆积的假设下，计算了PIC聚集体的三阶非线性极化率。我的非线性形象...
The results of transient degenerate four-wave mixing (DFWM) and “pump-probe” spectroscopy in aggregates of 1,1′-diethyl-2,2′-cyanine (pseudoisocyanine, PIC) chloride at 300 K are reported. Spectral dispersion of DFWM efficiency within the J-band and near exciton resonance has been measured. Time response of both transient absorption changes and DFWM signal is found to be strongly dependent on pump photon fluence and wavelength. This behavior is qualitatively explained within a physical model of nonlinear optical dynamics in aggregate domains which accounts for exciton annihilation, and the effect of nonthermal phonons produced as a result of decay of two-exciton states. Intensity-dependent evolution of excess dynamic disorder due to nonthermal phonons manifests itself in pump-probe experiments as dispersion-type differential spectrum appearing at high pump intensity. The third-order nonlinear susceptibility of PIC aggregates has been calculated supposing highest density packing. The nonlinear figure of me...