Circularly Polarized Optical Feedback Effects on the Polarization of VCSEL Emission

This letter investigates experimentally the effects of circularly polarized optical feedback (CPOF) on the polarization characteristics of vertical-cavity surface-emitting lasers (VCSELs). It is shown that CPOF imparts up to 30% circular polarization to the VCSEL emission. The degree of circular polarization acquired by the VCSEL emission is determined by the feedback power ratio and the VCSEL bias current. The effects of COPF have been compared to the influence of other species of linearly polarized optical feedback.