Polarization-independent resonant lattice Kerker effect in phase-change metasurface

TL;DR

This paper demonstrates a polarization-independent resonant lattice Kerker effect in phase-change metasurfaces, enabling reconfigurable, high-transmittance wavefront control with broad tuning capabilities.

Contribution

It introduces the first polarization-independent resonant lattice Kerker effect using GST disks, allowing dynamic and scalable phase modulation in metasurfaces.

Findings

Achieved polarization-independent Kerker effect with GST metasurfaces.

Enabled large-range tunability of operation wavelength and GST crystalline fraction.

Realized a reconfigurable Huygens' metasurface with near 2π phase control.

Abstract

Resonant lattice Kerker effect in periodic resonators is one of the most interesting generalizations of the Kerker effect that relates to various fascinating functionalities such as scattering management and Huygens metasurfaces. However, so far this effect has been shown to be sensitive to the incident polarization, restricting its applications. Here, we report, for the first time, polarization-independent resonant lattice Kerker effect in metasurfaces composed of periodic Ge$_2$Se$_2$Te$_5$ (GST) disks. For such a metasurface of square lattice, the spectrally overlap of the electric dipole and magnetic dipole surface lattice resonances can be realized by choosing an appropriate GST crystalline fraction regardless of the incident polarization. The operation wavelength and the required GST crystalline fraction can be conveniently tuned over large ranges since these parameters scale linearly with the disk size and the lattice period, greatly facilitating the design. Making use of the obtained resonant lattice Kerker effect, we realize a reconfigurable and polarization-independent lattice Huygens' metasurface with a dynamic phase modulation of close to $2\pi$ and high transmittance. This work will advance the engineering of the resonant lattice Kerker effect and promote its applications in phase modulation and wavefront control.