Influence of Low-Frequency Modulation on Polarization Switching of VCSELs Subject to Optical Feedback

The influence of low-frequency modulation on the polarization switching (PS) properties of vertical-cavity surface-emitting lasers (VCSELs) under optical feedback has been investigated experimentally. The current modulation frequency has a large impact on the PS of VCSELs even in the low-frequency range between 1 and 100 kHz. Thermal effects play an important role in this phenomenon.