Highly Stable Single Polarization Operation of GaInAs/GaAs Vertical-Cavity Surface-Emitting Laser on GaAs (311)B Substrate under High-Speed Modulation

Abstract

We have demonstrated a dynamically stable polarization mode GaInAs/GaAs vertical-cavity surface-emitting laser (VCSEL) grown on a GaAs (311)B substrate. The fabricated device exhibited a stable and single polarization under DC and high-speed modulation. Under DC operation, the orthogonal polarization suppression ratio (OPSR) was larger than 30 dB. We measured the time-resolved OPSR using square-wave modulation. It was found that the orthogonal mode was suppressed even for the first peak of the relaxation oscillation with OPSR>17 dB. In a 5 Gbps non-return-to-zero (NRZ) pseudo-random bit sequence (PRBS) modulation experiment, the OPSR was greater than 27 dB. These stable and single polarization characteristics were due not only to the anisotropic optical gain on a (311)B substrate, but also strained GaInAs/GaAs quantum wells and the thin oxide layer which was employed in this experiment.