Phase Hologram by Acoustic Metasurfaces

Conventional acoustic metamaterial‐based holograms primarily focus on generating 3D images through acoustic amplitude or intensity fields, which represent energy distributions perceivable by an observer. In these earlier approaches, the phase is typically considered unimportant at the image plane. However, from the perspective of information transmission, phase serves as a valuable carrier, holding information equivalent to that of the amplitude channel. In this research, the concept of an acoustic phase hologram by metasurfaces is introduced. This advanced approach decouples the phase from the amplitude distribution through an iterative optimization design process. To validate the concept, a hologram in the phase channel is numerically and experimentally designed and demonstrated. Compared to conventional amplitude holograms, the approach offers significant advantages, including lower transmission loss and strong anti‐interference ability. This conceptual breakthrough holds strong potential for applications across various domains, particularly in acoustic and optical communications and wave imaging.