Symmetric and asymmetric spectra of acoustic waves resonantly transmitted through a slab in a fluid

We theoretically studied the resonant transmission of acoustic waves through a slab in a fluid. When acoustic waves are incident on the interface perpendicularly, Bright-Wigner type resonances occur, whereas Fano resonances are observed when acoustic waves are obliquely incident. We examine various resonance peaks in transmission using analytical expressions for the transmittance. In particular, we show that an antiresonance occurs when two types of resonance overlap at the same frequency. (C) 2020 The Japan Society of Applied Physics