Constant-intensity waves in non-hermitian media

Abstract

When waves propagate through a non-uniform potential landscape their interference typically gives rise to a complex intensity pattern. In this chapter we review our work on how to entirely suppress these intensity variations by adding system-specific gain and loss components to the potential. The resulting constant-intensity (CI) waves are entirely free of interference fringes and get perfectly transmitted across any such non-Hermitian scattering landscape that is put in their way. We discuss how to generalize this concept to more than one dimension and to the non-linear regime where these special wave states open up the way to study the phenomenon of modulation instability in non-uniform potentials. Experimental implementations of these unique wave states are envisioned not just in optics, but also in other fields of wave physics such as in acoustics.