Figure 1
From: Broadband non-reciprocal transmission of sound with invariant frequency
Design and behavior of the acoustic non-reciprocal device with invariant frequency and near-unity forward transmission.
(a) Schematic of the configuration of the broadband non-reciprocal device. (b) The spatial intensity distribution of the waves coming from the two opposite directions, showing the underlying mechanism responsible for the frequency-invariant rectification phenomenon. The forward (Orange arrow) and the reverse (Blue arrow) directions can be generally defined as the propagating directions of the wave incident from the side of loss and gain materials, respectively. The dotted-line arrow indicates that the transmission along this direction virtually vanishes.
