[17a-A32-1~11] 3.1 光学基礎・光学新領域

11:45 〜 12:00英語発表

[17a-A32-11] Tight focusing of dark C point singularities with radial or azimuthal polarization

〇(P)SUSHANTA KUMAR PAL¹ (1.Centre for Optics Photonics and Lasers, University Laval, Canada)

キーワード：

Optical vortex、Polarization singularity、Tight focusing

Structured light beams embedded with polarization singularities have brought significant breakthroughs to super-resolution imaging, optical communication, optical activity measurements, and atmospheric optics. At a polarization singularity, one or more parameters characterizing the state of polarization (SOP) of the beam, such as azimuth and handedness, are undefined. Polarization singularities are found in the light beams with spatially varying polarization states. The singularities of ellipse fields, in which the predominant SOPs are elliptical, are C points; at a C point, the SOP is circular. Tight focusing of polarization singularities has been studied for fundamental and advanced applications. In this article, we study the tight focusing of right-handed radially and azimuthally polarized dark C point polarization singular beams. A radially polarized dark C point polarization singularity can be generated by the coaxial superposition of two orthogonal circular basis beams with orbital angular momentums 1 and 3 respectively. By introducing a 180-degree phase difference between the orthogonal circular polarization states a radially polarized dark C point can be converted to an azimuthally polarized dark C point. Simulation results for right-handed radially and azimuthally polarized dark C-point singularities are presented. It is shown that unlike the conventional radially polarized beam the radially polarized dark C point polarization singular beam generates a donut structure of total intensity distribution and longitudinal intensity distribution at the focal plane.