We analyze polarization switching in Vertical Cavity Surface Emitting Lasers
taking into account a proper semiconductor frequency-dependent complex
susceptibility and spin-flip processes. Thermal effects are included as a
varying detuning, and gain differences arise from birefringence splitting. We
find that for large birefringence, gain differences between the two linearly
polarized modes are preponderant and switching occurs due to thermal shift. For
small birefringence, a polarization switching from the high-gain to the
low-gain mode occurs due to the combined effect of birefringence and
semiconductor phase-amplitude coupled dynamics for a finite value of the
carrier spin flip rate.
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