Scattering of Electromagnetic Wave by system of core/shell microsphere and nanoparticle

The paper deals with the scattering of an electromagnetic plane wave by a system of core/shell microsphere and a single nanoparticle placed outside the spheres. Backscattering intensity perturbation caused by the nanoparticle was studied, and it was found that the position of the inner sphere can be used as a new effective tool to both detect a particle and to determine its size. The system of core/shell microsphere provides a longer particle detection distance compared with a single sphere system. It is shown that the maximum value of the perturbation of backscattering is reached at the interspherical distance corresponding to the maximal energy of the electromagnetic wave concentrated in the vicinity of the nanojet.