100‐mW room‐temperature cw laser operation at 7300 A˚ has been achieved in a Ga1−xAlxAs (x∼0.22), ∼300 A˚ thick, single quantum well double heterostructure diode grown by organometallic vapor phase epitaxy. The proton‐delineated stripe contact is 6 &mgr;m wide, and the front and rear laser facets are coated for antireflection and high reflection respectively. The cw threshold current is 86 mA for a 250‐&mgr;m‐long device, and linear output power versus current characteristics are observed up to 100 mW with an external differential quantum efficiency of 1 W/A (59%). cw output power exceeds 13 mW at 100 °C. Between 25–55 °C, the pulsed threshold current varies exponentially with temperatureTas exp(T/T0), whereT0∼187 K.