SPATIOTEMPORAL CHARACTERISTICS OF FILAMENTATION IN BROAD-AREA SEMICONDUCTOR-LASERS

Using the time-dependent rate equations appropriate for semiconductor lasers, we perform a linear stability analysis to derive an analytic e xpression for the filament gain as a function of the filament spacing, oscillation frequency, linewidth-enhancement factor, pumping level, a nd nonlinear refractive index. The spatio-temporal characteristics of filamentation are obtained for a given set of operating parameters by maximizing the filament gain. Our theory predicts that there is a crit ical value of the linewidth-enhancement factor below which broad-area lasers remain stable even at high pumping levels, Moreover, under cert ain conditions, the self-defocusing Kerr-type nonlinearity can be used to suppress filamentation even when the linewidth-enhancement factor exceeds this critical value.