Memory effect for polarization of pump light in optically pumpedvertical-cavity semiconductor lasers

摘要

We report that the polarization of the emission of an opticallynpumped vertical-cavity surface-emitting laser (VCSEL) is sensitive tonthe polarization state of the pump light. By measuring this memoryneffect for circularly polarized pump light, we determine the normalizednrelaxation rate of the carrier spin, Γs, which is anvital parameter in current theoretical models of VCSEL polarization. Wenfind Γs=300±150, a value which is significantlynlarger than previously estimated. We also observe a memory effect fornthe orientation of linearly polarized pump light. This signals that,napart from the carrier spin, the VCSEL polarization is also determinednby the carrier momentum