Intensity rate equations to describe polarisation switching in vertical-cavity surface-emitting lasers

Summary form only given. Switching between two orthogonal linear polarisations in the fundamental mode of vertical-cavity surface-emitting lasers is the object of intensive experimental and theoretical work. Although several models have been proposed, experimental evidence suggests that gain/loss differences between the two modes is an important factor in polarisation switching. However, this view has never been mathematised. In this contribution we study analytically and numerically a class of simple intensity rate equations for a semiconductor laser with two nearly degenerate modes. In our model, the gain is current dependent to describe the gain shift relative to the cavity modes.