Enhanced multi-band acoustic sensing from quasi-bound states in the continuum

Abstract

The acoustic sensing is of vital importance in many areas. Here, we propose a one-port multi-resonator structure with multiple quasi-bound states in the continuum (QBICs) to achieve enhanced multi-band acoustic sensing. The one-port multi-resonator structure is constructed by inserting the multiple resonators into the one-port waveguide in sequence. When heights of these resonators are appropriate, the multiple QBICs can be obtained in the one-port multi-resonator structure. From these QBICs, the high pressure gains in multiple frequency bands can be realized at these resonators’ tops and are observed in experiments. In addition, the one-port multi-resonator structure is applied to the weak signal detection. Within multiple frequency bands, harmonic, periodic impulse, and modulated signals are significantly enhanced. These results demonstrate that the designed one-port multi-resonator structure well realize enhanced multi-band acoustic sensing and has the good potential for weak signal detection in practical applications, such as multiple fault diagnosis and multi-band communication.