One-way propagation of acoustic waves

one-way propagation, non-reciprocal transmission, acoustic diode, acoustic rectifier, nonlinearity, phononic crystal, granular media, radiation pressure, acoustic switch

Resume

The origin of electrical diodes dates back over a century. These are the first elements able to correct a energy flow. Despite the many applications envisioned for the wave diodes (optical, thermal and acoustical), the area remains relatively weakly developed.

The main objective of this research topic is to proposed new architectures for breaking the reciprocity of an acoustic system. Consequently, the intrinsic physics of each architecture is studied for understanding the internal limitations which is primordial for improving the proposed solutions.

Previous Works

During my PhD thesis, we proposed new architectures for breaking the reciprocity of an acoustic system.

Schematic diagram of the acoustic rectifier.

An acoustic rectifier based on the self-demodulation effect

First, a first architecture for asymmetrical transmission of elastic waves in a mono-mode guide mode is presented. This system is obtained by combining a selection layer and a conversion layer: the selection is provided by a phononic crystal while the conversion is performed by an unconsolidated granular medium via the self-demodulation effect. A quantitative experimental study of this acoustic rectifier indicates a strong asymmetry of transmission, up to 10^6, with wide band (10 kHz) and an audible effect.

Schematic principle of the concept of acoustic diode.

An acoustic diode using the acoustic radiation pressure

The second part is devoted to the development of a second non-reciprocal system based on the acoustic radiation pressure to a water-air interface. In a tri-layer water-air-solid, an incident acoustic wave from the solid layer meets a high impedance break and is mainly reflected. An incident wave from the water layer produces a deformation of the interface which can establish a contact between water and solid thus going to reduce tri-layer to a water- solid bilayer having good transmission without distortion wave. The concept is tested on a prototype and demonstrated a transmission asymmetry (above to 10^8) leading to several interesting applications for achieving acoustic wave controls like an acoustical switch also realized here.

[A3] Thibaut Devaux, Alejandro Cebrecos, Olivier Richoux, Vincent Pagneux, Vincent Tournat, Acoustic radiation pressure for nonreciprocal transmission and switch effects, Nature Communications 10, 3292 (2019). [PDF] [Supp. Mat.]

[A2] Thibaut Devaux, Vincent Tournat, Olivier Richoux, Vincent Pagneux, Asymmetric acoustic propagation of wave packets via the self-demodulation effect, Phys. Rev. Lett. 115, 234301 (2015). [PDF] Selected as Editors' Suggestion