Optical near-field scattering in a tip-sample system: A Green's function approach

16th International Youth Scientific School 'Actual Problems of Magnetic Resonance and its Applications'

Rogov, A.M.^1 ; Gazizov, A.R.^1 ; Kharintsev, S.S.^1 ; Salakhov, M.Kh.^1

Department of Optics and Nanophotonics, Institute of Physics, Kazan Federal University, Kremlevskaya 16, 420008 Kazan, Russia^1

关键词: Comparative analysis;    Dielectric substrates;    Dipolar approximations;    Green's function approaches;    Metallic nanoantenna;    Metallic nanoparticles;    Polarizability models;    Scattered intensity;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/478/1/012015/pdf
DOI  :  10.1088/1742-6596/478/1/012015

来源: IOP

【 摘 要 】

The optical near-field contribution to the total scattered intensity for a spherical metallic nanoparticle close to a dielectric planar interface is analytically calculated using a Green's function formalism. This system is suited for probing a specimen of interest on a dielectric substarte with a taper optical metallic nanoantenna. Based on the effective polarizability model we find a Green's function in the dipolar approximation, that allows one take into account the presence of the dielectric substrate. In particular, we provide evidence that the latter noticably influences the near-field contribution and it should necessarily be included in the generalized formalism for calculating the Green's functions for Raman scattering and fluorescence. A comparative analysis of the analytical model and finite-difference time domain based numerical simulation is performed.