Polarization dynamics of a multimode vertical-cavity surface-emitting laser subject to orthogonal optical injection

摘要

We have studied the effect of orthogonal optical injection on a multitransverse-mode vertical-cavity surfaceemitting laser (VCSEL). The injection beam comes from a similar VCSEL. Our results reveal that, when the receiver operates with several strong transverse modes of parallel polarization, optical injection can induce polarization switching in all of them while only one mode is locked to the external frequency. The induced switching can occur for a very weak (a few microwatts) injected beam. Periodic oscillations and low-frequency irregular pulsations are observed as well. © 2012 Optical Society of America.