Domenikou Natalia, Thanopulos Ioannis, Yannopapas Vassilios, Paspalakis Emmanuel
Materials Science Department, School of Natural Sciences, University of Patras, 26504 Patras, Greece.
Department of Physics, National Technical University of Athens, 15780 Athens, Greece.
Nanomaterials (Basel). 2022 Mar 21;12(6):1020. doi: 10.3390/nano12061020.
We study the nonlinear optical rectification of an inversion-symmetry-broken quantum system interacting with an optical field near a metallic nanoparticle, exemplified in a polar zinc-phthalocyanine molecule in proximity to a gold nanosphere. The corresponding nonlinear optical rectification coefficient under external strong field excitation is derived using the steady-state solution of the density matrix equations. We use electronic structure calculations for determining the necessary spectroscopic data of the molecule under study, as well as classical electromagnetic calculations for obtaining the influence of the metallic nanoparticle to the molecular spontaneous decay rates and to the external electric field applied to the molecule. The influence of the metallic nanoparticle to the optical rectification coefficient of the molecule is investigated by varying several parameters of the system, such as the intensity and polarization of the incident field, as well as the distance of the molecule from the nanoparticle, which indirectly affects the molecular pure dephasing rate. We find that the nonlinear optical rectification coefficient can be greatly enhanced for particular incident-field configurations and at optimal distances between the molecule and the metallic nanoparticle.
我们研究了一个与金属纳米颗粒附近的光场相互作用的反演对称破缺量子系统的非线性光学整流，以靠近金纳米球的极性锌酞菁分子为例。利用密度矩阵方程的稳态解，推导了外部强场激发下相应的非线性光学整流系数。我们使用电子结构计算来确定所研究分子的必要光谱数据，并使用经典电磁计算来获得金属纳米颗粒对分子自发衰变率以及施加到分子上的外部电场的影响。通过改变系统的几个参数，如入射场的强度和偏振，以及分子与纳米颗粒之间的距离（这间接影响分子纯退相速率），研究了金属纳米颗粒对分子光学整流系数的影响。我们发现，对于特定的入射场配置以及分子与金属纳米颗粒之间的最佳距离，非线性光学整流系数可以大大增强。
