Presentation Information

[23a-12B-11]Tight focusing of fractional C-point singularities

〇(P)SUSHANTA KUMAR PAL1 (1.COPL University Laval, Canada)


Optical vortex,Polarization singularity,Tight focusing

The scientific communities widely study spatially varying polarization distributions hosted with polarization singularities due to their diverse applications. At a polarization singularity, one or more parameters that define the state of polarization (SOP) of the light field are indeterminate. The optical fields in which the predominant SOP is elliptical are called ellipse fields. The singularities of ellipse fields are C-points and at a C-point the SOP is circular. The generic C-point singularities are named Lemon type, Monstar-type, and Star type. Shaping the focal plane intensity distributions of an optical field has been widely studied for fundamental research and advanced applications. Here, we study the tight focusing of two left-handed fractional C-point polarization singularities. A fractional C-point singularity can be realized by the coaxial superposition of two orthogonal circular basis beams, where one interfering beam carries the fractional orbital angular momentum (OAM). Simulation results for two different left-handed fractional C-point singularities are presented in the figure. The fractional C-points shown in row I and row II are generated by interfering with a left-circularly polarized Gaussian beam with right-circularly polarized Gaussian vortex beams of OAM 0.2 and 0.5 respectively. It is found that for a fractional C-point singularity, the strengths of constituent focal plane intensity distributions vary significantly with the OAM value.