Fujihashi Yuta, Ishizaki Akihito, Shimizu Ryosuke
Department of Engineering Science, The University of Electro-Communications, Chofu 182-8585, Japan.
Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki 444-8585, Japan.
J Chem Phys. 2024 Mar 14;160(10). doi: 10.1063/5.0189134.
Ultrafast optical spectroscopy is a powerful technique for studying the dynamic processes of molecular systems in condensed phases. However, in molecular systems containing many dye molecules, the spectra can become crowded and difficult to interpret owing to the presence of multiple nonlinear optical contributions. In this work, we theoretically propose time-resolved spectroscopy based on the coincidence counting of two entangled photons generated via parametric down-conversion with a monochromatic laser. We demonstrate that the use of two-photon counting detection of entangled photon pairs enables the selective elimination of the excited-state absorption signal. This selective elimination cannot be realized with classical coherent light. We anticipate that the proposed spectroscopy will help simplify the spectral interpretation of complex molecular and material systems comprising multiple molecules.
超快光学光谱学是研究凝聚相中分子系统动态过程的一种强大技术。然而，在包含许多染料分子的分子系统中，由于存在多种非线性光学贡献，光谱可能会变得拥挤且难以解释。在这项工作中，我们从理论上提出了基于用单色激光通过参量下转换产生的两个纠缠光子的符合计数的时间分辨光谱学。我们证明，使用纠缠光子对的双光子计数检测能够选择性地消除激发态吸收信号。这种选择性消除用经典相干光无法实现。我们预计，所提出的光谱学将有助于简化包含多个分子的复杂分子和材料系统的光谱解释。
