Humble Travis S, Cina Jeffrey A
Department of Chemistry and Oregon Center for Optics, University of Oregon, Eugene, Oregon 97403-1253, USA.
J Phys Chem B. 2006 Sep 28;110(38):18879-92. doi: 10.1021/jp0567669.
We formulate two-color nonlinear wave-packet interferometry (WPI) for application to a diatomic molecule in the gas phase and show that this form of heterodyne-detected multidimensional electronic spectroscopy will permit the reconstruction of photoinduced rovibrational wave packets from experimental data. Using two phase-locked pulse pairs, each resonant with a different electronic transition, nonlinear WPI detects the quadrilinear interference contributions to the population of an excited electronic state. Combining measurements taken with different phase-locking angles isolates various quadrilinear interference terms. One such term gives the complex overlap between a propagated one-pulse target wave packet and a variable three-pulse reference wave packet. The two-dimensional interferogram in the time domain specifies the complex-valued overlap of the given target state with a collection of variable reference states. An inversion procedure based on singular-value decomposition enables reconstruction of the target wave packet from the interferogram without prior detailed characterization of the nuclear Hamiltonian under which the target propagates. With numerically calculated nonlinear WPI signals subject to Gaussian noise, we demonstrate the reconstruction of a rovibrational wave packet launched from the A state and propagated in the E state of Li2.
我们制定了用于气相双原子分子的双色非线性波包干涉测量法（WPI），并表明这种外差检测多维电子光谱形式将允许从实验数据重建光诱导的振转波包。使用两个锁相脉冲对，每个脉冲对与不同的电子跃迁共振，非线性WPI检测对激发电子态布居的四线性干涉贡献。结合以不同锁相角进行的测量可分离出各种四线性干涉项。其中一项给出了传播的单脉冲目标波包与可变三脉冲参考波包之间的复重叠。时域中的二维干涉图指定了给定目标态与一组可变参考态的复值重叠。基于奇异值分解的反演程序能够从干涉图重建目标波包，而无需事先详细表征目标传播所依据的核哈密顿量。对于受高斯噪声影响的数值计算的非线性WPI信号，我们展示了从Li2的A态发射并在E态传播的振转波包的重建。
