Semiconductor Lasers with Integrated Optical Delay: A Nonlinear Dynamics Lab

In recent years, the role of delay in nonlinear systems, arising from a finite propagation time of signals, has become a focus of interest. This talk concerns feedback and coupling delay introduced by a passive section within multisection lasers. Although being only few ps long,
this delay gives rise to a rich world of dynamical phenomena, which can be controlled by dc injection currents. Exploiting these possibilities, we have experimentally prepared and studied the following scenarios: undamping of relaxation oscillations, two-mode pulsations due to amplified feedback, synchronization of delay-coupled oscillators, torus-breakup and period doubling routes to chaos, excitability at homoclinic bifurcations as well as of chaotic attractor ruins, coherence resonance of noisy precursors of Hopf and torus-birth bifurcations. Examples will be presented together with a theoretical discussion of the experimental findings.