POLARIZATION CONTROL IN A VERTICAL-CAVITY SURFACE-EMITTING LASER SUBMITTED TO OPTICAL FEEDBACK

We study experimentally and theoretically two polarization effects in a vertical cavity surface emitting laser submitted to optical feedback . In a first experiment, we obtain flips between two linearly polarize d laser modes up to a frequency of 50 MHz wing an external cavity with a polarizer In a second experiment, polarization self modulation is d emonstrated up to a frequency of 2.6 GHz, using a quarter wave plate i nstead. Numerical calculations, based on a four levels model for the a ctive medium, show a good agreement with the experiments.