Concentric Space-variant Linear Polarization of Light Generated by Dielectric Metalens
WenHao Chang1*, JunHan Lin2, ChiehHsiung Kuan2, SsuYen Huang1, YannWen Lan3, TingHua Lu3
1Department of Physics, National Taiwan University, Taipei, Taiwan
2Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan
3Department of Physics, National Taiwan Normal University, Taipei, Taiwan
* Presenter:WenHao Chang,
Spatial and polarization degrees of freedom for optical communications have been widely discussed recently. However, miniaturized flat and ultrathin optical components with such features become more and more important on the subwavelength scales in the phase, amplitude and polarization of light. Here, we use a nanostructured dielectric metalens to generate a concentric polarization beam with different orientations along the radial direction and present the polarization states of light at the spatial distribution. The important discovery is that the rotation of the nanostructures on metalens strongly correlate to the linear polarization orientations of the transmitted light at near field. Owing to the design of the metalens, the polarization state can be manipulated from near field to focal point. The variation of the spatial polarization states transformed by the dielectric metalens can be properly mapped onto hemi-Poincaré sphere. We believe that the variety of spatial polarization within a minimized configuration provides a new degree of freedom for diverse applications in the future.

Keywords: space-variant, circular polarized light, linear polarized light, polarization states, metalens