Spectral broadband dynamics of semiconductor lasers with resonant short cavities

We present a semiconductor laser system tailored to exhibit unusual spectral broadband emission dynamics. We study the dynamics properties and its physical origin in detail and discuss the potential of this system as a high-power incoherent laser light source. Our semiconductor laser (SL) system comprises a particularly long edge-emitting laser of 1.6 mm length and a short external cavity of comparable length. We have adjusted for resonant coupling conditions between both cavities, such introducing strong modal coupling. By varying the pumping or the optical feedback phase, we obtain a characteristic cyclic scenario evolving from stable emission via a period-doubling cascade to chaos and back to stable emission. We find distinct differences to the short-cavity regime of conventional nonresonant SL systems reported so far. The most prominent difference is the onset of chaotic intensity dynamics in conjunction with pronounced multimode dynamics of high optical bandwidth exceeding ~70.3em0exnm, therefore comprising more than 100 lasing longitudinal modes. In that sense, the presented system represents an excellent nonlinear dynamical model system offering well-controllable generation of distinct multimode dynamics. Furthermore, we demonstrate that the nonlinear dynamics properties allow for controlled adjustment of the coherence length in a wide range between ~1300.3em0exμm and ~80.3em0exm. This property facilitates application in novel measurement technology in which (in)coherence properties are of importance.