Visible laser diodes have been fabricated from AlGaInP operating at approximately 680 nm to high output powers. Broad area lasers with 100 μm wide emitting apertures operate to greater than 1 W CW with a differential efficiency of 38%. The threshold current densities of the material have been measured to be as low as 350 A/cm2 for lasers with 30% mirror reflectivities. Monolithic bars 8 mm long with 50 μm emitting apertures periodically spaced on 500 μm centres have been fabricated which operate to 8.5 W CW.