Double‐heterostructure (DH) injection lasers based on the GaAs1−xSbx/AlyGa1−yAs1−xSbx@qLsystem have been fabricated using liquid phase epitaxial growth techniques and operated at room temperature at wavelengths in the 1‐&mgr;m region. The observed room‐temperature threshold current densities, as low as 2100 A cm−2, are comparable to those of GaAs/AlGaAs devices of similar geometry.