A semiconductor laser device incorporates a beam control layer for
reducing far field and beam divergence. Within the beam control layer, a
physical property of the semiconductor material varies as a function of
depth through, the beam control layer, by provision of a first sub-layer
in which the property varies gradually from a first level to a second
level, and a second sub-layer in which the property varies from said
second level to a third level. In the preferred arrangement, the
conduction band edge of the semiconductor has a V-shaped profile through
the beam control layer.