Multiplexed interference metasurface for complete phase, amplitude, and polarization control

Phase, amplitude, and polarization are three fundamental properties of light. Controlling these properties at will is critical for promoting modern optical applications and revealing new light–matter interactions. However, most existing strategies are often influenced by the zeroth-order residual, or it can be hard to achieve complete control in a simple and compact manner. Here, we propose an approach that overcomes these difficulties using multiplexed interference metasurfaces by implementing the control in the diffraction channel. Specifically, phase control is achieved by the Pancharatnam–Berry (PB) phase mechanism, amplitude control is achieved by the interference, and polarization control is achieved by leveraging the conjugate relation of the PB phase for different circularly polarized (CP) light. As a proof-of-concept validation, three meta-gratings (MGs) and three polarization generation devices (PGDs) are experimentally demonstrated in the terahertz regime. Our approach provides a concise and analytical framework for light control with good performance, which holds promising potential for applications involving multiple beam generation and control.