Modelling Autler-Townes splitting and acoustically induced transparency in a waveguide loaded with resonant channels

TL;DR

This paper models acoustic wave behavior in a waveguide with resonant channels, revealing how different configurations lead to phenomena like Autler-Townes splitting and acoustically induced transparency, enabling advanced control of wave transmission.

Contribution

It introduces a unified model capturing both Autler-Townes splitting and acoustically induced transparency in waveguides with resonant channels, highlighting their combined control capabilities.

Findings

Autler-Townes splitting occurs with subwavelength channel separation.

Acoustically induced transparency arises from out-of-phase interference.

Combined mechanisms provide enhanced control over transmission spectra.

Abstract

We study acoustic wave propagation in a waveguide loaded with two resonant side-branch channels. In the low frequency regime, one-dimensional models are derived in which the effect of the channels are reduced to jump conditions across the junction. When the separation distance is on the scale of the wavelength, which is the case that is usually considered, the jump conditions involve a single channel and acoustically induced transparency (AIT) occurs due to out-of-phase interferences between the two junctions. In contrast, when the separation distance is subwavelength, a single junction has to be considered and the jump conditions account for the evanescent field coupling the two channels. Such channel pairs can scatter as a dipole resulting in perfect transmission due to Autler - Townes splitting (ATS). We show that combining the two mechanisms offers additional degrees of freedom to control the transmission spectra.