Stripe laser with transverse over gang.

In a transverse junction stripe laser (10), comprising a semiconductor substrate (11) supporting a semiconductor heterostructure of an active layer (13) sandwiched between higher bandgap cladding layers (12, 14), the novelty is that (i) the substrate surface has planar regions and inclined regions of different crystallographic indices; (ii) the active and cladding layers are epitaxially grown with an amphoteric dopant such that the layer sections on the planar regions are of first conductivity type and the layer sections on the inclined regions are of second conductivity type, thus forming one or more junctions (15, 16) in the active layer (13); and (ii) ohmic anode (20, 21) and cathode (22) contacts are provided for applying currents (23, 24) of at least threshold level to the junction(s).