Applying quantum tunnelling concept in the study of the coupling in acoustic waveguides

Abstract

However evanescent coupling between acoustic waveguides has been well studied by the mode-matching method in the literature, a proposed physical model based on the tunnelling concept is used to explain such coupling. Based on phonons being one type of quasi-particles, the Schrödinger equation for a phonon has been built by introducing a virtual mass and potential for phonons. This proposed model is physically intuitive and analytical. It can well explain the exponential dependence of the coupling length on the guide separation distances and the frequency of acoustic waves reported in the literature. The exponential dependent relationship between the coupling coefficients predicted by the proposed model agrees well with the experimental data reported in the literature. The model provides a new idea for understanding and studying coupling between acoustic waveguides.