Chaotic semiconductor laser systems—bandwidth enhancement predicted by numerical simulations

Numerical simulations using a traveling wave model are used to predict the radio frequency (rf) bandwidth and relative total rf power of chaotic output from a semiconductor laser (SL) with a delayed optical feedback system. By tailoring the linewidth enhancement factor (LEF) and nonlinear gain compression of the SL, improvements of a factor of two in the 80%-of-the-rf-power bandwidth, five in the rf bandwidth above 40 dB, and ten in the integrated rf power of the chaos, compared to values for a commercial-like SL, are predicted to be possible. The SL parameter values to be targeted will require device designers and fabricators to explore ways to decrease relaxation oscillation damping while, preferably, still achieving a high relaxation oscillation frequency. Higher values of LEF are a feature of poorer quality SLs of the past and can be expected to be achieved by reversion to past device recipes.