Misalignment-induced frequency locking in lasers

We study arrays of heterogeneous single-mode semiconductor lasers coupled through an external cavity with facet misalignments. This system can be modeled mathematically as a set of coupled nonlinear delay-differential equations. The heterogeneity, in the form of frequency detuning, is represented as parametric disorder between the oscillators, and the facet misalignments is represented by a small disordering of the time-delays in the coupling terms. In this system, we show that the introduction of time-delay disorder induces perfect frequency locking in a system that otherwise is unable to frequency-lock due to heterogeneous natural frequencies, as well as chaotic behavior.