Nonreciprocal sound propagation in space-time modulated media

Realization of nonreciprocal devices, such as isolators and circulators, is of fundamental importance in microwave and photonic communication systems. This can be achieved by breaking time-reversal symmetry in the system or exploiting nonlinearity and topological effects. However, exploration of nonreciprocal devices remains scarce in acoustic systems. In this work, sound propagation in a space-time modulated medium is theoretically studied. Finite-difference time-domain simulations are carried out to verify the results. Functionalities such as mode conversion, parametric amplification, and phase conjugation are demonstrated.

Duke Scholars

Author Steven A. Cummer Electrical and Computer Engineering