ESTIMATION OF SCATTERING LOSSES IN DIELECTRICALLY APERTURED VERTICAL-CAVITY LASERS

Dielectric apertures, formed by oxidation or wet-etching of high Al co ntent AlGaAs layers in vertical cavity lasers, have recently been used for improved device performance. In this letter an iterative numerica l analysis is used to estimate the excess optical losses as the device diameter is reduced. For smaller sizes, where single-mode devices are possible, the optical scattering losses become significant unless the aperture is tapered to approximate a perfect lens or is thin to appro ximate a weaker waveguide. (C) 1996 American Institute of Physics.