Multilayer broadband metasurface for ultra-low sidelobe OPA application in mid-infrared band

This letter proposes an all-solid-state, ultra-low sidelobe optical phased array (OPA) by arranging the broadband metasurface units in the mid-infrared band. Simulation results demonstrate that the OPA generates a specific or a continuous beam sweep between 0 degrees and 42.22 degrees as the 354.56 degrees phase modulation of the designed metasurface. A key feature of our design is that the maximum sidelobe energy of the OPA is only 4% of the main lobe energy within the total deflection angle, which depends on the reflectance fluctuation range of the broadband metasurface less than 11.91% during phase control.