Nonlinear Time-Reversal in a Wave Chaotic System

TL;DR

This paper demonstrates a nonlinear electromagnetic time-reversal mirror in a wave chaotic system with a discrete nonlinearity, enabling secure communication by reversing wave propagation in complex environments.

Contribution

It introduces a novel nonlinear time-reversal technique in wave chaotic systems and showcases its application for secure communication.

Findings

Successful implementation of nonlinear time-reversal mirror

Demonstration of secure communication using the system

Effective reversal of wave propagation in complex environments

Abstract

Exploiting the time-reversal invariance and reciprocal properties of the lossless wave equation enables elegantly simple solutions to complex wave-scattering problems, and is embodied in the time-reversal mirror. A time-reversal mirror operates by recording the wave disturbance as a function of time at one or more points in a medium, broadcasting a time-reversed version of the signal(s) in the opposite direction, and allowing the waves to reverse-propagate back to their origin. Here we demonstrate the implementation of an electromagnetic time-reversal mirror in a wave chaotic system containing a discrete nonlinearity, and, as an example of its utility, we have used it to demonstrate a new form of secure communication.