Polarization behavior of birefringent multitransverse mode vertical-cavity surface-emitting lasers

An analysis has been undertaken of the effect of birefringence on the selection of polarization states of a weakly index guided vertical-cavity surface-emitting laser (VCSEL) supporting both a fundamental and a first-order transverse mode. It is shown that for small index steps polarization switching due to spatial-hole burning effects can occur. For larger index steps it is found that higher order modes can emerge which are orthogonally polarized to the dominant polarization of the fundamental mode.