Performing broadband and tunable mathematical operations based on acoustic reconfigurable metasurfaces

Acoustic metasurfaces can manipulate acoustic waves at subwavelength scales, thus proved to have advantages in constructing novel compact analog computing (CAC) systems. Here, we design an acoustic CAC system based on a nondispersive focusing metasurface (FM) and a reconfigurable reflective metasurface (RRM), which can perform broadband and tunable mathematical operations. The nondispersive FM consists of the sandwich-like-structured units, featuring the non-dispersive effective refractive indexes and high transmission efficiency. The RRM is formed by the amplitude modulator (AM) and pi/2-phase modulator (pi/2-PM), where the moving regions in the AM and pi/2-PM can control the reflection amplitude and phase distribution of RRM, respectively. The numerical results show that the proposed CAC system can perform spatial differentiation and integration on the incident acoustic wave in the frequency range from 3.0 kHz to 3.9 kHz. This work promises the broadband and tunability that are critical for practical computing devices, paving the way towards acoustic computing applications, wave processing and manipulations.

Automated summary

This article introduces an acoustic compact analog computing system based on acoustic metasurfaces. The proposed system utilizes a nondispersive focusing metasurface and a reconfigurable reflective metasurface to perform broadband and tunable mathematical operations. Numerical results show that the system can achieve spatial differentiation and integration in the frequency range of the incident acoustic wave, highlighting its potential applications.