Suppression of modulation instability in VCSEL by external optical injection

The dynamics of a broad area semiconductor vertical-cavity surface-emitting laser (VCSEL) is analytically and numerically investigated considering the linewidth enhancement factor resulting in the modulation instability of a spatially homogeneous generation mode. We find the aperture width depends on the parameters of the laser system, above which the modulation instability leads to chaotic filamentalization of the optical field and complicates the practical application of such lasers. We show that using the external optical injection of small amplitude, it is possible both to transform chaotic filaments into regular stationary spatial optical structures (stripes and hexagons) and to stabilize the broad-area VCSELs.