Broadband polarization resolving based on dielectric metalenses in the near-infrared.

We demonstrate a novel polarization-resolved device (PRD) with the ability to accurately resolve the polarization states via a simple measurement process. The PRD is composed of two elaborately designed metalenses, which are capable of focusing the two circularly polarized (CP) lights. Therefore, for an arbitrary polarized light (treated as a combination of the two CP lights), a discrepancy is exhibited on focusing efficiency, which inversely provides a way to calculate the ellipticity. With such a strategy, the generalized form for polarization resolving is derived, with which the ellipticity of the incident polarized light can be calculated (through just measuring the efficiencies of the two spots). This process is accomplished by utilizing the numerical simulations and theoretical analysis. Moreover, resolving the polarization states can be achieved within a wavelength range of 400nm, due to the broadband effect of the designed metalenses. With the merits of compact configuration, broadband and compatibility with the existing semiconductor technology, the designed PRD holds potential applications in characterizing the polarization states.