Additively Manufactured Polarization Insensitive Broadband Transmissive Metasurfaces for Arbitrary Polarization Conversion and Wavefront Shaping
Jianfeng Zhu, Yang Yang, Jiexin Lai, J. Nulman
Abstract
Abstract Arbitrarily manipulating the polarization and wavefront of electromagnetic waves using ultrathin and highly efficient devices is desirable for many systems. Ultrathin broadband polarization‐insensitive transmissive metasurfaces, which can achieve the same polarization conversion and wavefront shaping for arbitrary linearly polarized incident waves, are proposed. The meta‐atom is composed of a transmitting antenna and a receiving antenna with a group of phase delay lines connecting them. The rotation of the transmitting antenna introduces the polarization conversion, and the different lengths of the transmission lines provide [−π, π] phase shift for wavefront shaping. Both the polarization conversion and wavefront shaping functions are polarization insensitive. Differential feeding is applied to both the transmitting and the receiving patch antennas to improve the transmission efficiency. The prototypes are conveniently printed by using the additive manufacturing technique. Two polarization‐insensitive metasurfaces are designed and measured to demonstrate. One of them produces vortex beams with 90° polarization conversion, and the other achieves anomalous refraction with 45° polarization conversion.