Distinction of Acoustically Induced Transparency and Autler-Townes Splitting by Helmholtz Resonators

Electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS) share similar transparent windows in the transmission spectrum, which causes confusion and difficulty in discriminating between them. Essentially, EIT involves asymmetric profile interference, while ATS originates from a strong coupling effect. The conventional method uses the Akaike information criterion (AIC) to calculate the proportion of EIT and ATS, and then determines the dominant phenomenon by experimental data fitting without considering fundamental differences in physics. We present two kinds of acoustic structures by grafting two Helmholtz resonators to a cylindrical tube whose geometrical parameters are chosen by individual mechanisms of acoustically induced transparency (AIT) and ATS. Our results explicitly show AIT and ATS phenomena analytically, numerically, and experimentally, which are also supported by data-fitting and AIC methods. This study contributes to the design of AIT and ATS in their specific applications, avoiding any confusion.