Tight focusing of orthogonal C-point polarization states

Abstract

Recently it is shown that spatially varying polarization distribution embedded with polarization singularity can be used to form an orthogonal basis pair. In this paper we show tight focusing of orthogonal basis pairs of bright and dark C-points. We observe that unlike orthogonal basis pairs of homogeneous polarization distribution, the orthogonal basis pairs of spatially varying polarization distributions embedded with C-points, show same intensity distribution at the focal plane upon tight focusing. We show that the focal plane intensity distribution is depend upon the intensity distribution of the beam under tight focusing. The longitudinal and transverse field components are hosted with phase vortices of charge ±1. Though the position of phase singularities remains same in a given orthogonal C-point pair, but the sign of phase vortices undergo reversal. The current study may reveal various other fundamental concepts related to polarization singularities.