Spin controlled optically pumped vertical cavity surface emitting laser

It is shown that the output polarisation of optically pumped vertical cavity surface emitting lasers (VCSELs) can be unambiguously controlled by the pump polarisation. The degree of the output polarisation is higher than that of the pump polarisation. It is concluded that the polarisation of VCSELs with spin polarised electrical pumping can be controlled even with low spin injection efficiencies.