We have successfully manipulated the electron-spin states in a GaAs vertical cavity surface emitting laser (VCSEL) as a way to control the polarization state of the lasing output at room temperature. We have demonstrated experimentally that the partial electron-spin alignment, created by optically pumping the GaAs active region with circularly polarized pulses, drastically changes the polarization state of the lasing output, producing circularly polarized lasing emission. We have found that the very long electron-spin lifetime available in the GaAs gain medium accounts for the special polarization properties in VCSEL structures.

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