Theoretical studies of polarization bistability in birefringent ARROW VCSELs

The polarization bistable characteristics of birefringent antiresonant reflection optical waveguide (ARROW) vertical-cavity surface-emitting lasers (VCSELs) under external optical injection is studied and juxtaposed theoretically with an equivalent index-guided device. The simulation results show that ARROW VCSELs exhibit bistable behaviour and have wider hytheresis loops. The wider hytheresis loop in ARROW VCSEL is attributed to the difference in the lateral profiles of the two polarization modes, resulting in the accentuation of the optical gain difference between the two polarizations. This is because the introduction of a birefringent ARROW has an equivalent effect of creating an anisotropic geometrical cavity in the laser structure. Our theoretical studies also show that the polarization bistability characteristics of ARROW VCSELS are not sensitive to small values of birefringence and can be easily tailored by varying the cladding thicknesses, an option that is not available to index-guided VCSELs.