Effect of spatial profile of gain and reflectivity in oxide-confined VCSELs

Summary form only given. Significant progress has been made in VCSELs using native oxide apertures to provide current confinement. It is believed that the oxide aperture provides index guiding to reduce the optical losses of the lasing modes. However, single transverse mode is only achieved with very small size lasers. In this paper, the modal behavior of the oxide-confined lasers are studied using two dimensional beam propagation method and multimode rate equations. We show that even a very thin oxide aperture can provide strong index guiding effect to drive the laser into multimode emission. We also show that by engineering the gain profile or the mirror reflectivity profile, a single fundamental mode emission can be obtained even for relatively large aperture VCSELs.