We report a study of threshold characteristics of as‐grown surface‐emitting lasers fabricated with molecular‐beam epitaxy by the monolithic integration of two quarter‐wave high reflectors (mirrors) of AlAs/Al0.4Ga0.6As surrounding an active spacer layer. The spacer was either a multiple quantum well of GaAs/Al0.4Ga0.6As (100 A˚/200 A˚) or GaAs. Several structures were grown corresponding to different mirror reflectance and different spacer thicknesses from ultrashort 0.9 to 10 &mgr;m. One of the structures was chemically etched to form a two‐dimensional array of microlasers. All of the structures were photopumped at room temperature, and the lasing threshold was determined. Without any lateral confinement, the threshold irradiance was as low as 2×105W/cm2. Near‐field images of the light emitted slightly above threshold reveal several competing filaments. This competition broadens the lasing linewidth, but can be controlled by lateral confinement schemes.