Polarization-switching influence on the intensity noise of vertical-cavity surface-emitting lasers

We experimentally investigate the influence of polarization switching on the intensity noise of transverse single-mode vertical-cavity surface-emitting lasers. We show that a polarization switch always leads to strong noise in the two individual orthogonal polarization modes over a large range of pump current in the vicinity of the switch, whereas the effect on the total emission noise strongly depends on the strength of the coupling between total intensity noise and polarization fluctuations, which is mainly determined by the amount of birefringence. Thus our results demonstrate that the occurrence of a polarization switch can have a strong deteriorating effect on the noise behavior, not only if polarization selection is present, but also on the total emission noise, and therefore has to be considered in future investigations and low-noise applications.