Acoustic metasurface hologram multiplexing by changing incident field
摘要
Multiplexed acoustic holograms have been recently realized by varying the modulated field of the metasurface, but attentions have been seldom focused on tailoring the incident profile due to the challenge of retrieving method. Here, we propose an acoustic metasurface holography that can produce multiple desired images by varying the incident fields. A modified iterative angular spectrum algorithm is proposed to calculate the phase profile of the hologram, which is further encoded into a reflective metasurface consisting of grooved units. Three examples are designed and the simulations confirm that multiple desired images can be successfully reconstructed under different incidences, such as spherical waves with different center locations, vortex beams with different topological charges, and planar waves with different incidence angles. The proposal shows a promising avenue to realize multifunctional acoustic devices and information encryption.