Recent advances in the performance of GaInAsSb/AlGaAsSb quantum-well diode lasers have been directly related to improvements in the quality of the molecular-beam epitaxy (MBE)-grown epitaxial layers. These improvements have been based on careful measurement and control of lattice matching and intentional strain, changes in shutter sequencing at interfaces, and a generally better understanding of the growth of Sb-based epitaxial materials. By using this improved MBE-grown material, significantly enhanced performance has been obtained for midinfrared lasers. These lasers, which are capable of approximately 2-mum emission at room temperature, presently exhibit threshold current densities of 143 A/cm2, continuous wave powers of 1.3 W, and diffraction-limited powers of 120 mW. Such high-performance midinfrared diode lasers are of interest for a wide variety of applications, including eye-safe laser radar, remote sensing of atmospheric contaminants and wind turbulence, laser surgery, and pumping of solid-state laser media.