Wideband chaos generation using VCSELs with intensity-modulated chaotic optical injection

We propose what we believe to be a novel approach for generating wideband chaos via intensity-modulated chaotic optical injection, utilizing chaotic signals produced by a free-running vertical-cavity surface-emitting laser. Two injection configurations are considered: parallel injection and orthogonal injection. Specifically, we examine the effect of injection parameters, including injection strength and frequency detuning, on the chaos radio frequency spectrum bandwidth. The numerical simulation confirms that intensity modulation can destroy the injection-locking state which occurs in unidirectional injection and increase the chaos bandwidth by introducing additional frequency components. For this system, the chaotic region extends over the entire parameter space having, in some cases, chaos bandwidths more than double that of free-running chaos, with a maximum bandwidth of 47.9 GHz.