Bistability and torus break-up in a semiconductor laser with phase-conjugate feedback

We present a detailed study of a route to chaos via quasiperiodicity on a torus in a semiconductor laser with phase-conjugate feedback. Highlighting the use of new tools that go far beyond mere simulation, we compute bifurcation diagrams and unstable manifolds of saddle periodic orbits. In this way, we show how a torus breaks up with a final sudden onset of chaos in a crisis bifurcation. We also identify regions of bistability between periodic solutions and other attractors in the system.