Fig. 2: Ultra-broadband CAFAB metasurface design and its performance.

a Phase distribution of superposition of cubic phase and lens phase. b Left: schematic diagram of the meta, right: top view and side view of the meta. c The polarization conversion efficiency (PCE) of the metasurface when the incident wavelength is 440 nm–640 nm. d Scanning electron microscopy (SEM) image of the details of a fabricated polarization-dependent metasurface.