Helicity-dependent metasurfaces employing receiver-transmitter meta-atoms for full-space wavefront manipulation

Manipulating orthogonal circularly polarized (CP) waves independently in both reflection and transmission modes in a single metasurface is pivotal. However, independently controlling CP waves with different polarizations is difficult especially for both reflection and transmission modes. Here, we designed a receiver-transmitter metasurface with helicity-dependent reflection and transmission properties. Our design breaks the fixed phases of the geometry metasurface-carrying Pancharatnam-Berry operators by combining the receive and transmit antennas. To verify the effectiveness of the modulation, we designed three linear deflectors with: (a) reflection phase gradient, (b) transmission phase gradient, and (c) both of gradients to achieve anomalous reflection, anomalous refraction, and simultaneous anomalous reflection and refraction, respectively. As proof of the concept, a bifunctional meta-device with functions of anomalous reflection and focusing transmission for different incident CP waves was simulated and measured. Our findings offer an easy strategy for achieving arbitrary bifunctional CP devices. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement