Diffraction from oxide confinement apertures in vertical-cavity lasers

Direct measurement of scattered fields from oxide confinement apertures in vertical-cavity lasers is presented. Diffraction fringes associated with ea ch transverse lasing mode are detected in the far field from devices with v arying oxide aperture dimensions and with quantum efficiencies as high as 4 8%. The diffracted pattern symmetries match the rectangular symmetry of the oxide apertures present in the devices and fringe locations are compared t o Fraunhofer theory. The fraction of power diffracted from the lasing mode remains roughly constant as a function of relative pump rate, but is shown to depend on both transverse mode order and oxide aperture size. (C) 1999 A merican Institute of Physics. [S0003-6951(99)03532-9].