Hybrid‐Phase Assisted Amplitude and Phase Control Using Full‐Space Metasurface

Abstract

Achieving independent control of phase and amplitude is pivotal yet challenging for electromagnetic (EM) wave manipulation. Metasurface provides an efficient recipe to this challenge, but most of the work reports so far are still confined in half space (transmission or reflection) and manipulation of linearly polarized EM waves, restricting itself from integrating more functionalities with complex wavefronts into one optoelectronic device. Here, a hybrid phase approach synthesizing propagation and geometric phases is proposed to achieve independent and arbitrary control of amplitude and phase response for circularly polarized (CP) wave in full space by using a non‐interleaved single‐celled metasurface. To validate the concept, a full‐space dual‐channel meta‐hologram is experimentally demonstrated, manifesting images of letters “T” and “R” at lower and upper frequencies (f1 and f2), respectively. The finding of full‐space metasurface opens new possibilities to control CP waves by simultaneous amplitude and phase modulations, which is important for high‐capacity wireless communications, as well as sophisticated functionality, and other advanced meta‐devices.