Polarization-Stable 980 nm Vertical-Cavity Surface-Emitting Lasers with Diamond-Shaped Oxide Aperture

Polarization-stable 980 nm oxide-confined vertical-cavity surface-emitting lasers with 3 μm diamond-shaped aper- ture are fabricated by comprehensively utilizing the anisotropic properties of wet etching and wet nitrogen oxida- tion of Ⅲ-Ⅴ semiconductor materials. Polarization-stable operation along the major axis of the diamond-shaped oxide aperture with 11 dB orthogonal polarization suppression ratio is achieved in a temperature range of 15-55℃ from the threshold to 4 mA.

Power-induced polarization switching and bistability characteristics in 1550-nm VCSELs subjected to orthogonal optical injection

The polarization switching（PS） and polarization bistability（PB） characteristics of a 1550-nm vertical-cavity surfaceemitting laser（VCSEL） subjected to orthogonal optical injection are systematically investigated.The simulated results show that the PS and polarization-resolved nonlinear dynamical states of the VCSEL are critically dependent on the changing paths of the injected power.The polarization dynamics for different scanning directions of the injected power is presented to explain the polarization evolution during the formation of PS.In the case of forward scanning injected power,with the increase of frequency detuning level between the VCSEL and the injected light,the injected power required for PS gradually increases for negative frequency detuning but exhibits fluctuations for positive frequency detuning.In the case of reversely scanning injected power,the injected power required for PS displays fluctuant changes within the whole frequency detuning range.Specifically,PS may disappear under certain negative frequency detuning and large bias current.Furthermore,the hysteresis width as a function of the frequency detuning is calculated,and the regions for the appearance and disappearance of PB have been determined in the parameter space of the bias current and frequency detuning.