A semiconductor laser device comprises, on top of an active layer, an n-type
cladding
layer of Alx1Ga1-;x1As and a p-type cladding layer of (AlxGa1-;x)yIn1-;yP
for defining a barrier height. The p-type cladding layer for defining a barrier
height contains more component elements than the n-type cladding layer. The potential
difference between the conduction band edges of the p-type cladding layer for defining
a barrier height and the active layer is greater than the potential difference
between the conduction band edges of the n-type cladding layer and the active layer.
The carriers in the active layer are prevented from overflowing into the p-type
cladding layer and a material having a high thermal conductivity is used for the
n-type cladding layer to prevent the phenomenon of thermal saturation, thereby
providing improved optical output.
