Single-Layer Transmissive Chiral Plasma Metasurface with High Circular Polarization Extinction Ratio in Visible Wavelength

Abstract

Chiral metamaterials are extensively applied in the fields of photoelectric detection, biomedical diagnostics and micro-nano polarization imaging. Currently, single-layer chiral metamaterials are unfortunately limited by several issues, such as a weaker circular polarization extinction ratio and circular polarization transmittance difference. To tackle these issues, a single-layer transmissive chiral plasma metasurface (SCPMs) suitable for visible wavelength is proposed in this paper. Its basic unit is composed of double orthogonal rectangular slots and a spatial π/4 inclined arrangement of the rectangular slot to constitute a chiral structure. Each rectangular slot structure has characteristics that enable the SCPMs to easily achieve a high circular polarization extinction ratio and strong circular polarization transmittance difference. Both the circular polarization extinction ratio and circular polarization transmittance difference of the SCPMs reach over 1000 and 0.28 at a wavelength of 532 nm, respectively. In addition, the SCPMs is fabricated via the thermally evaporated deposition technique and focused ion beam system. This compact structure coupled with a simple process and excellent properties enhances its applicability for the control and detection of polarization, especially during integration with linear polarizers, to achieve the fabrication of a division-of-focal-plane full-Stokes polarimeter.