Concentric Space-variant Linear Polarization of Light Generated by Dielectric Metalens

WenHao Chang^1*, 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, email:jp6cl6@gmail.com

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