Low-loss phase change materials-based reprogrammable non-volatile 1 × 2 switch on integrated metasurfaces

With their profound ability to manipulate electromagnetic waves, metasurfaces are at the forefront of a revolution in modern optics and photonics. Despite significant advancements, the quest for programmable and controllable metasurfaces remains hampered by the slow response times and the static nature of conventional materials. This study introduces a reconfigurable integrated coding metasurface-based optical switch using low-loss phase change materials, which specifically utilizes the dynamic properties of antimony trisulfide ( $S{b}_2{S}_3$ ) enabling programmable control of the functionality of the metasurface. The device can steer the output between two ports, achieving a large extinction ratio, with an insertion loss of around -2.1 dB and -11 dB crosstalk. Furthermore, the device is analyzed for various imperfections in the fabrication process and shows a robust performance despite such imperfections.