Bifurcation analysis of coupled laser modes in mutually delay coupled lasers

This paper considers a system of two semiconductor lasers that are mutually coupled face to face, so that they receive each other's light after a fixed delay time. The lasers are assumed to be identical, except for a possible detuning of their free-running frequencies. The coupled laser modes of a rate equation model with delay are studied with tools from bifurcation theory, especially numerical continuation. This reveals a comprehensive geometrical picture, which is organized by the unfoldings for nonzero detuning of pitchfork bifurcations that exists for zero detuning.