Research Progress for Multifunctional Switching Based on Phase Change Material Metasurfaces

Metasurfaces, artificially engineered with periodic subwavelength meta-atoms, can flexibly and effectively manipulate the inherent properties of electromagnetic waves, such as amplitude, polarization, phase and propagation mode. Thus, metasurfaces have attracted great attention in recent years. However, the optical functions of most metasurfaces are static, which cannot realize the dynamic control of electromagnetic waves. Compared with static metasurfaces, reconfigurable metasurfaces can realize the active switching of optical functions by introducing different external excitations without changing the metasurface design. In this paper, we present a few research achievements to review the research progress of phase change material metasurfaces in multifunctional switching. The design principles and applications of multifunctional switching metasurfaces are introduced in detail from four configurations, in which the GST material operates as the unit cell, film, embedded gap and programmable structure. Finally, the future direction and applications of phase change material metasurfaces are presented.