Fig. 3: Design principle of reconfigurable acoustic holography.

a Process for generating an acoustic phase hologram, and the binary mechanism for modulating the acoustic wave. A phase delay of π occurs between the transmission wave when propagating through crystalline and amorphous PCL. b Simulated results showing the evolution of acoustic interference along the wave propagation path. c Modulus patterns rewritten on the same PCL film. d Simulated and experimental ripple patterns based on the reconstructed acoustic fields. The distance between the target plane and the PCL film was fixed at 20 mm. All the scale bars are 10 mm.