Spin angular momentum at the sharp focus of a cylindrical vector vortex beam
Автор: Kotlyar V.V., Stafeev S.S., Telegin A.M.
Журнал: Компьютерная оптика @computer-optics
Рубрика: Дифракционная оптика, оптические технологии
Статья в выпуске: 6 т.47, 2023 года.
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Sharp focusing of a light field with double (phase and polarization) singularity is studied. Using the Richards-Wolf method, an exact analytical expression for the longitudinal projection of the spin angular momentum (SAM) vector at the focus is obtained. The expression derived suggests that 4 ( n -1) subwavelength regions are formed at the focus, where n is the cylindrical vector beam order, with their centers located on a certain circle centered on the optical axis. Notably, the SAM projections are found to have the opposite sign in the neighboring regions. This means that in the neighboring focal regions, the light has alternating left or right elliptical polarization (manifestation of a spin Hall effect). At the center of the focal spot near the optical axis, the field is right-handed elliptically polarized at m > 0, or left-handed elliptically polarized at m 0, and clockwise for m
Spin angular momentum, tight focusing, cylindrical vector beam, optical vortex
Короткий адрес: https://sciup.org/140303254
IDR: 140303254 | DOI: 10.18287/2412-6179-CO-1347