Versatile Polarization Conversion and Wavefront Shaping Based on Fully Phase‐Modulated Metasurface with Complex Amplitude Modulation

Abstract The fully phase‐modulated metasurfaces, implementing independent wavefront control of output cross‐ and co‐polarized components under circularly polarized (CP) incidence, can effectively break the shackles that the Pancharatnam–Berry phases and spin‐decoupled metasurfaces can only manipulate the cross‐polarization component. With this, the scheme of complex amplitude modulation is introduced as a new degree of freedom, which can further modulate the intensity and phase of the output cross‐polarized (co‐polarized) component, and thus become an alternative approach for designing multi‐functional polarization manipulation metasurfaces. Three representative metasurfaces are verified with particular polarization conversion and wavefront shaping, demonstrating the flexibility and practicability of the design scheme. Such a concept opens up a new platform for multifarious integrated optics through harnessing the new degree of freedom and may further accelerate the development of metasurface polarization optics.