Multifunctional full-space metasurface controlled by frequency, polarization and incidence angle

Multifunctional metasurfaces have exhibited considerable abilities of manipulating electromagnetic (EM) waves, especially in full-space manipulation. However, most works are implemented with functions controlled by polarization or frequency and seldom involve the incidence angle. Herein, we propose a multifunctional full-space metasurface controlled by frequency, polarization and incidence angle. A meta-atom is firstly designed. When EM waves illumine normally in the C-band, it possesses the characteristic of asymmetric transmission with high-efficient polarization conversion. In the Ku-band, both x- and y-polarized EM waves along both sides will be reflected and achieve broadband and high-efficient cross-polarization conversion. Also, when illumined obliquely, both sides can achieve efficient retroreflection at a certain frequency. As a proof of concept, a metasurface consisting of the above meta-atoms is configured as a dual orbital angular momentum (OAM) vortex beam generator and different beam deflector when illumined normally. Meanwhile, it acts as a multi-channel retroreflector when illumined obliquely. Both the simulated and measured results show excellent performances. Our findings provide a new degree of freedom to design multifunctional metasurfaces that can further promote applications. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

This study introduces a multifunctional full-space metasurface controlled by frequency, polarization, and incidence angle. By designing meta-atoms, efficient electromagnetic wave conversion and reflection are achieved in different bands and incident angles. The metasurface is configured as a dual OAM vortex beam generator and beam deflector under normal illumination, as well as a multi-channel retroreflector under oblique illumination.