We study topological variations of polarization singularity lines in the electric field of electromagnetic radiation reflected from a parabolic mirror irradiated by elliptically polarized Gaussian and Laguerre-Gaussian beams and two types of Poincaré beams. Torus knots and links of the singular lines of polarization appear as a result of their tight focusing in the reflected radiation. Variation of the polarization ellipticity degree of the Gaussian and Laguerre-Gaussian beams and the parameters defining the polarization distribution of the Poincaré beams causes transformation of the singular lines located near the focal point of the mirror, which is accompanied by a variety of decouplings and reconnections. The total linking number of the singular lines of different types predominantly remains constant upon these reconnections.

• Received 24 March 2023
• Accepted 25 May 2023

DOI:https://doi.org/10.1103/PhysRevA.107.063506