For the first time, high performance GaAs/GaAlAs surface‐emitting lasers with internal 45° micromirrors, which totally reflect and emit the beam from the substrate in junction‐down configuration, have been demonstrated. The 45° and 90° mirrors of the device were fabricated by using ion milling and reactive ion etching techniques, respectively. Typical threshold current density of 440 A/cm2, external differential efficiencies of 52%, and output power in excess of 1 W under quasi‐cw operation have been achieved.