Polarization sensitivity of injection-locked VCSELS

The spin flip model (SFM) is extended to analyse the behaviour of vertical-cavity surface-emitting lasers (VCSEL) subject to optical injection with linear polarization. The effect of birefringence and spin relaxation rate on the stable locking region in the plane of injected optical power versus frequency detuning is investigated. It is found that increased birefringence or reduced spin relaxation rate cause the stable locking region to begin at higher injected power and detuning. Regions of quasi-stability are also identified for certain combinations of parameters, characterised by sinusoidal oscillations of very small amplitude in the optical field components.