Delay Induced Excitability

TL;DR

This paper investigates how time-delayed feedback induces excitability in bistable systems, demonstrating theoretical, experimental, and numerical evidence of delay-induced excitability leading to wave phenomena.

Contribution

It introduces the concept of delay-induced excitability in bistable systems, supported by theoretical analysis, laser experiments, and numerical simulations of coupled systems.

Findings

Existence of delay-induced excitability in asymmetric bistable systems

Experimental observation of excitability in laser polarization dynamics

Numerical demonstration of wave-fronts and spirals due to delay effects

Abstract

We analyse the stochastic dynamics of a bistable system under the influence of time-delayed feedback. Assuming an asymmetric potential, we show the existence of a regime in which the systems dynamic displays excitability by calculating the relevant residence time distributions and correlation times. Experimentally we then observe this behaviour in the polarization dynamics of a vertical cavity surface emitting laser with opto-electronic feedback. Extending these observations to two-dimensional systems with dispersive coupling we finally show numerically that delay induced excitability can lead to the appearance of propagating wave-fronts and spirals.