Interplay of excitability and spatial effects in vertical-cavity surface-emitting optical amplifiers

• Applicant: Dr. Markus Sondermann
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: from 2005 to 2006
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 12939216

Spatio-temporal phenomena are observed in many natural systems as well as in laboratory experiments. An effect that is often observed in chemical and biological systems is the interplay of spatial degrees of freedom and excitability, a concept that describes the perturbation-independent response of a system once the perturbation amplitude has surpassed a certain threshold level. Only very recently the existence of excitable waves that travel in the direction orthogonal to the propagation of the emitted light has been demonstrated in a semiconductor optical amplifier, i.e., a semiconductor laser that is operated below its lasing threshold and optically injected by a master laser. Semiconductor lasers and optical amplifiers are devices of high technological relevance as well as paradigms of non-linear dynamical systems in optics. Therefore, it is the aim of this project to explore what different kinds of excitable waves do exist in these devices and to characterize their spatial and temporal dynamics, including the interaction of several of the excitable waves. These waves might prove to be useful in possible concepts of all optical communication. Moreover similarities and differences of excitable spatial waves in semiconductor optical amplifiers and other media are to be highlighted. For example, new possibilities in the interaction behaviour of excitable waves in semiconductor optical amplifiers were predicted theoretically. Thus, the understanding of excitable spatial structures in general is hoped to be enriched.

• DFG Programme: Research Fellowships
• International Connection: Spain
• Host: Dr. Salvador Balle Monjo