Elliptically polarized light obtained from tilted high-contrast grating VCSELs

We show that ultrathin elliptically polarized VCSELs can be realized with standard high-contrast gratings (HCGs) whose bars are tilted to the semiconductor crystalline axes on the transverse plane, without relying on any 2D chiral layer. Revisiting orthogonal polarization suppression ratio (OPSR) measurements, we demonstrate that the reduced OPSR for tilted gratings is related to elliptical lasing polarization rather than degraded polarization selectivity. Simulations confirm that the polarization state can be tuned by balancing intrinsic and HCG-induced anisotropies. These devices provide integrated elliptically polarized and wavelength-tunable sources for chip-scale atomic devices.