3-D Printed Transmission-Reflection-Integrated Metasurface for Spin-Decoupled Full-Space Quadruplex Channels Independent Phase Modulation

This article demonstrates 3-D printed transmission-reflection-integrated (TRI) metasurfaces (MSs), which achieve full-space spin-decoupled channels with independent phase modulation. Under a circularly polarized (CP) incident wave illumination, the phase of left-hand circularly polarized (LHCP) and right-hand circularly polarized (RHCP) channels in the reflecting and transmitting spaces can be independently controlled. The meta-atom comprises linearly polarized (LP) patches at the top and bottom with phase delay lines connecting them. In the reflecting space, varying the size of the LP patch provides the same dynamic phase shifting for the LHCP and RHCP channels. Meanwhile, globally rotating the meta-atom introduces Pancharatnam–Berry (P–B) phase shifting for the reflected co-polarization channel. Thus, the LHCP and RHCP channels in the reflecting space can be fully decoupled. As for the transmitting space, the phase delay lines provide the same dynamic phase shifting for the LHCP and RHCP channels. Meanwhile, locally rotating the transmitting antenna provides opposite geometric phase shifting for the LHCP and RHCP channels. Thus, the LHCP and RHCP channels in the transmitting space can be decoupled as well. To demonstrate, different TRI MSs achieving quadruplex channel multiplexing under CP wave illuminations are simulated and experimentally verified.