| Abstract: | We investigate both experimentally and numerically a complex structure,where 'face-to-face' Helmholtz resonance cavities(HRCs) are introduced to construct a one-dimensional acoustic grating.In this system,pairs of HRCs can intensely couple with each other in two forms:a bonding state and an anti-bonding state,analogous to the character of hydrogen molecule with two atoms due to the interference of wave functions of sound among the acoustic local-resonating structures.The bonding state is a 'bright' state that interferes with the Fabry-Perot resonance mode,thereby causing this state to break up into two modes as the splitting of the extraordinary acoustic transmission peak.On the contrary,the anti-bonding state is a 'dark' state in which the resonance mode remains entirely localized within the HRCs,and has no contribution to the acoustic transmission. |
