Recent advances in electromagnetic metamaterials and metasurfaces for polarization manipulation

Abstract

Polarization is an important characteristic of electromagnetic waves that has been exploited in many areas of wave manipulations. While effective control of polarization is highly demanded in various applications, traditional polarization converters have drawbacks such as large volume, narrow operating frequency band, low efficiency, and high losses, hindering themselves from practical applications. Metamaterials and metasurfaces are recently developed artificially structured electromagnetic materials constructed by three- or two-dimensional arrays of meta-atoms with tailored electromagnetic responses, exhibit great potential in controlling the propagation of electromagnetic waves and are highly suitable for flexible control of polarization. Here, we review the recent developments in the field of electromagnetic metamaterials and metasurface for polarization manipulation, focusing on their operation principles and practical applications. We discussed the research progress of chiral metamaterials and anisotropic metasurfaces, and also summarized the achievements of metasurfaces for comprehensive manipulation polarization and phase in recent years. We further summarize the recent achievements on the diversified polarization manipulation functions of metasurfaces. Finally, we discuss reconfigurable metasurfaces that can dynamically control the polarizaiton and wavefronts of electromagnetic waves, including not only electrically reconfigurable metasurfaces with constitutional meta-atoms locally tuned by external stimuli, but also time-modulated metasurfaces exploiting the temporal dimension by applying dynamic switching of the coding sequences. Finally, we look forward to the possible future directions and existing challenges in this rapidly developing field.