Injection Locking Bandwidth in 1550-nm VCSELs Subject to Parallel and Orthogonal Optical Injection

The injection locking properties of two commercially available 1550-nm vertical-cavity surface-emitting lasers (VCSELs) have been analyzed experimentally and theoretically in this work. The injection locking diagrams in the plane of frequency detuning versus injected power have been experimentally measured for both devices subject to parallel- and orthogonal-polarized optical injection into the two polarizations of the fundamental mode. Differences in the injection locking bandwidth are experimentally observed when the devices are subject to parallel or to orthogonal-polarized optical injection. A theoretical model based on the Fabry-Perot method has been developed to reproduce the measured stability maps of both 1550-nm VCSELs subject to parallel-polarized optical injection into the parallel polarization lasing mode showing excellent agreement between theory and experiments.