Self-consistent rate-equation theory of coupling in mutually injected semiconductor lasers

A rate-equation theory is derived for the coupling of two Fabry-Pérot semiconductor lasers. The effective coupling coefficients depend on the respective inversions in each individual laser, where the latter are modified by the coupling. Stable single-mode operation is investigated and locking ranges are calculated for lasers coupled by a linear coupler with given reflection and transmission coefficients. For a case of coupling via self-imaging in a multi-mode interference anti-phase reflector, the shapes of output-intensity curves agree well with measured curves.