Y-shaped phononic demultiplexer based on Fano and acoustically induced transparency resonances in one dimensional asymmetric/symmetric loops structure

Abstract

In this work, we present an analytical demonstration of the possibility to realize a simple phononic demultiplexer based on Fano and Acoustically Induced Transparency (AIT) resonances. The demultiplexer is a Y-shaped waveguide with an input line and two output lines (called also channels). The first output line is composed of a segment (guide) of length d1 and two symmetric/asymmetric loops of lengths d2 and d3, the second output line contains a segment of length d4 and two symmetric/asymmetric loops of lengths d5 and d6. We derive the analytical expressions for a selective transfer of a single propagation mode through one line by keeping the other line unaffected. This AIT resonance is characterized by a maximum transmission peak wedged between two transmission zeros. The existence of a complete transmission beside a transmission zero (Fano resonance) enables the selection of a given frequency in the first output line, by canceling the transmission in the second output line and the reflection in the input line. The position and the quality factor of these resonances are sensitive to the geometrical parameters of the segments and loops which should be chosen appropriately. The effect of the symmetric and asymmetric loops on the transmission spectra of our proposed demultiplexer is also discussed. The theoretical results are obtained out using the continuous medium interface response theory, which makes it possible to calculate the Green function of any composite material. This allows us to determine the two transmission rates T1, T2 and the reflection rate R. This structure can be used as high performance and high transmittance acoustic guiding, demultiplexing and noise filtering.