We report on gas-source molecular beam epitaxy growth of GaAs/GaInAsP quantum well lasers emitting at 0.87 μm. The active region of this aluminum-free laser structure consisted of a single 12-nm-thick GaAs quantum well layer sandwiched between GaInAsP confinement layers. The lasers exhibited low threshold current density of about 270 A/cm2 and high characteristic temperature (190 K). The internal quantum efficiency and internal waveguide loss were 83% and 3.3 cm−1, respectively. Ridge waveguide lasers having 6×500 μm2 ridge dimensions produced 78 mW continuous-wave light output power per facet at room temperature, with an external differential quantum efficiency of 72%. A fundamental lateral mode operation was maintained up to 65 mW per facet.