Fully controlled photonic spin in highly confined optical field

Shuoshuo Zhang, Shenggui Fu, Huanian Zhang, Xiaolu Ge, Zhidong Bai, Yudong Lyu, Rui Zhao, Zhongsheng Man
2019 Optics Express  
As an intrinsic attribute of light, the spin angular momentum (SAM) of photons has aroused considerable attention because of the fascinating properties emerging from light-matter interactions. We show that a diffraction-limited focal field with a steerable photonic spin structure in three dimensions can be produced under a 4π microscopic system. This is achieved by focusing two counter-propagating configurable vector beams produced in the coherent superposition of three different beams with
more » ... larization, y-polarization, and radial-polarization. By altering the amplitude factors of these resultant beams, the ratios between the three mutually orthogonal polarized components can be freely tuned within the focal plane, thereby allowing dynamic control over the spin orientation and ellipticity of the tightly focused optical field. The results demonstrated in this paper may find applications in spin-controlled nanophotonics.
doi:10.1364/oe.27.033621 pmid:31878426 fatcat:cfre7sm4kbawpcnbh2n7v3vteq