This paper investigates some of the properties of continuous wave (CW) (AlGa)As-GaAs injection lasers with Al in the active region. The active region gain at threshold

th is estimated as a function of Al concentration in the active region. The basic configuration is a five-layer structure with GaAs as the two outer regions; the center region is Al
yGa
1-yAs and the two surrounding layers are Al
xGa
1-xAs .