A Tunable Metasurface Deflector Based on MIM Waveguide Filled with Phase-Change Material

Metasurfaces hold great promise for overcoming the limitations of conventional refractive and diffractive optics due to their unique electromagnetic properties. Nevertheless, most of the functional metasurfaces are static. Besides, beam-steering only is discretely realized for no more than three states. A new strategy for on-chip planar metasurface is proposed to realize tunable light manipulation. Benefit from fast phase transitions of phase-change material and linear gradient phase generated by metasurfaces, continuously beam-steering within ± 60° at 10.6 μm can be achieved in metal-insulator-metal (MIM) waveguide. Moreover, the number of addressable point of the scanning deflector is theoretically estimated to be 12, about 4 times of the previous report. The designed deflector with compact size and reconfigurable functionalities may have potential for applications in multifunctional photonic circuits.