Design of AlOx/GaAs high-index contrast subwavelength gratings for 940nm VCSELs

High-index contrast subwavelength gratings (HCG) for 940 nm GaAs-based VCSELs were presented. The structural characteristics of TM-HCG is analyzed, especially the influence of the grating parameters on the high reflection band. The 940nm TM-HCG has a large reflection bandwidth up to 188nm (Delta lambda / lambda(0) = 20%) with its reflectivity more than 99.5% for TM incident light, and reflectivity is less than 67.5% for TE incident light. So the HCG exhibits large high reflectivity bandwidth and polarization selectivity.