ИСТИНА

The singularities of polarized light, such as the points of purely circular or purely linear polarization, appear naturally in many processes of light-matter interaction. The vast majority of research on polarization singularities is performed within paraxial approximation, which implies that the planes of polarization ellipses in propagating light beams and pulses are perpendicular to their axes. However, in more general kind of non-paraxial electromagnetic fields, which consist of plane waves travelling in different directions, all three Cartesian components of the electric field vector are present and the polarization ellipse can have any possible orientation of its plane. The main properties of polarization singularities in such fields were described in [1], but there are few papers that deal with these objects in real experiments or physical models. A perfect example of non-paraxial light is the near-field of the metal nanoscale objects in plasmon resonance. In our work we consider the interaction of the golden spheroidal particle with the plane incident monochromatic wave. The distribution of the near-field was earlier found analytically in [2]. By means of linear interpolation over three-dimensional net we obtained the structure of lines of circular and linear polarization (C-lines and L-lines) and visualized it in wide range of the incident radiation parameters. The near-field of a nanoparticle contains two closed C-lines and two closed L-lines that are linked. The topological structure of the lines was shown to be remarkably stable: the number of the lines and their mutual entanglement remained unchanged for different angles of incidence of the plane wave and its different polarization states. Authors acknowledge the support of Russian Foundation for Basic Research, grant 18-32-00217 [1] M. V. Berry, J. Opt., 6, 657-678 (2004) [2] E. Chubchev, Yu. Vladimirova, V. Zadkov, Opt. Express., 22, 20432-20445 (2014)