A complex amplitude control method of metasurface based on full phase modulation

•In this work, we propose a complex amplitude control method of metasurface based on full phase modulation.•The complex amplitude of the co-polarized component of the incident circular-polarized light is controlled by the circular nanopillars, and the complex amplitude of the cross-polarized component is controlled by the rectangular nanopillars. Unlike the Pancharatnam-Berry phase and spin-decoupled metasurface, which only modifies the phase of the cross-polarization components, the full-phase modulation metasurface achieves independent wavefront control of the co– and cross-polarization components of circularly polarized waves. As a result, a novel concept for multifunctional manipulation of the metasurface is presented in this paper, which is a complex amplitude control method based on full-phase modulation via a metasurface. This method allows for simultaneous and independent amplitude and phase manipulation of the co– and cross-polarization components of circularly polarized waves. At 980 nm wavelength, the results of complex amplitude control for incident circularly polarized light (left circularly polarized or right circularly polarized) demonstrate the feasibility of the method.