ONE-WAY PROPAGATION OF WAVES: NONLINEARITY CAN!
Deterministic chaos, fractal structures and other beautiful phenomena are
manifestations of the nonlinear character of forces which govern our world.
Besides a revolutionary change in our approach to predictability, these
discoveries had great impact on technological applications. In this letter a
new unexpected effect of nonlinearity is discovered which may lead to new
technologically important devices: the possibility to control wave transmission
by breaking the simmetry between opposite propagation directions.
The simplicity of the model and the great generality of the results which-
by exploiting distinctive nonlinear properties of materials like
multistability and resonance shifts, lead to asymmetric wave transmission-
will likely allow actual implementation e.g. in layered media with suitably
tailored nonlinear properties.
The attached figure is a dramatic illustration of the effect: a wavepacket
coming from the left passes trough the wall (the nonlinear medium). If the
packet comes from the right it is reflected back!
