Delay-induced switched states in a slow-fast system

We consider the two-component delay system εx(t) = −x(t) − y(t) + f(x(t − 1)), y(t) = ηx(t) with small parameters ε, η and positive feedback function f. Previously, such systems have been reported to model switching in optoelectronic experiments, where each switching induces another one after approximately one delay time, related to one round trip of the signal. In this paper, we study these delay-induced switched states. We provide conditions for their existence and show how the formal limits ε → 0 and/or η → 0 facilitate our understanding of this phenomenon. This article is part of the theme issue 'Nonlinear dynamics of delay systems'.