Aperture placement effects in oxide-defined vertical-cavity surface-emitting lasers

A study of the effects of aperture placement on the properties of vertical-cavity surface-emitting lasers (VCSEL's) is presented, When thin apertures are placed at the peak of the electric field standing wave optical losses are very high for small apertures. The threshold current increases with decreasing aperture size and two-dimensional diffraction like patterns are evident in the far field. For apertures placed at a node, optical losses appear to be negligible, and loss of optical confinement is apparent for apertures below 2 mu m.