Coherent perfect absorption can only be realized at specific resonant frequencies or in narrow bands,which greatly limits its usefulness in practical applications.In recent years,the introduction of non-Hermitian modulation and acoustic metamaterials has provided new research ideas for complex acoustic wave manipulation,and resulted in many novel wave-matter interactions that are difficult to realize in natural structures.In this paper,we propose a non-Hermitian acoustic subwavelength cavity-tube coupling model to theoretically derive and demonstrate the evolution of coherent perfect absorption.Coalescence of two coherent perfect absorptions with a bandwidth averaging factor of 12.825 is realized by tuning the non-Hermitian parameters of the system,and the corresponding broadband perfect absorbing characteristics are observed on the output spectra.This work provides a new way to realize broadband coherent perfect absorption based on non-Hermitian acoustic metamaterials,and also lays a theoretical foundation for the development of new functional devices for broadband acoustic absorption,acoustic detection and other engineering applications.
维普
万方数据