Polarization-controlled 850-nm-wavelength vertical-cavity surface-emitting lasers grown on [311]B substrates by metal-organic chemical vapor deposition

Abstract

We demonstrate the polarization stability of 850-nm-wavelength vertical cavity surface-emitting lasers (VCSELs) grown on [311]B substrates under continuous-wave (CW) and dynamic operation. To clearly verify the polarization stability of VCSELs on [311]B substrates due to the anisotropic optical gain, the characteristics of both VCSELs on [311]B and [100] substrates were compared experimentally. Under CW operation, very small difference in both orthogonal polarization suppression ratio and the distribution of polarization direction was observed between VCSELs on [311]B and [100] polyimide-buried structures. On the other hand, significantly larger orthogonal polarization suppression ratio was obtained for VCSELs on [311]B substrates than those on [100] substrates under zero-bias modulation. Time-dependent orthogonal polarization suppression ratio measurements also showed that the orthogonal polarization suppression ratios of the VCSEL on [311]B substrates were more stable than those on [100] substrates. The data transmission characteristics also indicate large differences in the dependence of the bit error rate on bias current and the power penalty between polarization resolved and unresolved systems between VCSELs on [311]B and [100] substrates. The beneficial effect of the polarization stability of VCSELs on [311]B substrates due to their anisotropic optical gain is clearly demonstrated.