Stably polarized 795 nm Vertical-Cavity Surface-Emitting Lasers with Anti-phase SiNx Surface Gratings

795 nm vertical-cavity surface-emitting lasers (VCSELs) with dielectric surface gratings to control the output polarization are designed and fabricated. The calculated results demonstrate that a well-designed SiN x surface grating positioned on the surface of an anti-phase VCSEL structure enhances the reflectivity difference between the two polarization modes compared to a conventional GaAs surface grating, consequently resulting in a larger gain anisotropy in VCSELs and a high orthogonal polarization suppression ratio (OPSR). Characterization shows that a peak-to-peak OPSR of 30.3 dB is achieved at 85°C for 795 nm VCSELs with a SiN x surface grating of 5 µm in diameter and an oxide aperture of ∼4µm, demonstrating the effectiveness of the SiN x surface grating in polarization control for 795 nm VCSELs.