ИСТИНА

We analyze theoretically modification of the resonance fluorescence spectrum of a two-level atom driven by a linearly polarized monochromatic field near the plasmonic nanostructure, which we consider to be for simplicity a metallic nanospheroid, as a function of the geometric parameters of the nanospheroid and the atom’s location relative to the nanospheroid [1]. The influence of the plasmonic nanoparticle was taken into account by using effective values (modified by the nanoparticle) for the Rabi frequency and the linewidths in the expression for the resonance fluorescence spectrum. It is shown that one can control this spectrum varying the aspect ratio of the nanospheroid and the atom’s location around the nanospheroid, as well as by the polarization of the incident laser field [2]. These parameters affect the local field enhancement and the modification of the total decay rate of the atom interacting with the nanospheroid, which leads to modification of the resonance fluorescence spectrum of the atom (frequency shift of the satellite lines in the Mollow-type triplet, widths of the lines and the spectrum intensity) by contrast with that one in free space. It is shown that by varying the aspect ratio of the spheroid one can vary the radiative decay rate in the range of 10-2 to 106 of the decay rate in free space. Distribution of the near-field in the vicinity of the nanospheroid and atomic decay rates have complicated structures and drastically depend on the aspect ratio. The correct selection of the aspect ratio of the nanospheroid allows controlling the intensity of the fluorescence signal. References: 1. Resonance fluorescence of a two-level atom in the vicinity of a plasmonic nanosphere was analyzed in: Yu. V. Vladimirova, V. V. Klimov, V. M. Pastukhov, and V. N. Zadkov, “Modification of two-level-atom resonance fluorescence near a plasmonic nanostructure,” Phys. Rev. A 85, 053408 (2012). 2. E.D. Chubchev, Yu. V. Vladimirova, and V. N. Zadkov, “Controling near-field polarization distribution of a plasmonic prolate nanospheroid by frequency and polarization of the incident electromagnetic field,” submitted for publication (2014).