Nonlinear Waves and Turbulence in Photonics 2022 - Abstract

Rotter, Stefan

Perfect transmission and absorption of arbitrary wavefronts

In my talk, I will demonstrate how to organise the interference process of waves passing through a system in such a way that all of these waves-independently of their wavefront- are perfectly transmitted or perfectly absorbed. In the first case, I will consider a disordered medium that scatters any incoming wave very strongly. As I will show, even such a structureless medium can be made fully transmitting to all incoming wavefronts by putting a customised complementary medium in front of it [1]. This special situation is achieved when the reflection matrices of the two media surfaces facing each other satisfy a matrix generalization of the condition for critical coupling. For the case of perfect absorption, I will discuss how the interferometric absorption effect known as “coherent perfect absorption", can be generalised from a single mode to arbitrarily many modes. Using a cavity with two lenses in a telescope configuration and a critically coupled absorber inside of it, we demonstrate that any incoming wavefront, even a complex speckle pattern perturbed by atmospheric turbulences, is absorbed with close to perfect efficiency in a massively parallel interference process [2].


[1] Horodynski, Kühmayer, Ferise, Rotter & Davy, arXiv:2203.05429 (Nature, in print)

[2] Slobodkin, Weinberg, Hörner, Pichler, Rotter & Katz, arXiv:2205.05478