Index-guided laser on grooved (001) substrate

A semiconductor device comprising:

• a substantially (001) substrate doped with receptors for carriers of a first conductivity type, said substrate having a first and second surfaces which are substantially parallel to each other, said substrate further having third and fourth surfaces which join said first and second surfaces so that said second, third, and fourth surfaces form a groove and such that said third surface is declined from the first surface a minimum of 5 degrees and a maximum given by the {111} plane;
• a first cladding layer doped with receptors for carriers of said first conductivity type and which covers said groove and at least part of said first surface of said substrate such that said first cladding layer follows the contours of said groove;
• an active region adjacent to said first cladding layer and disposed over said groove such that said active region follows the contours of said groove, said active region having a first phase with a first bandgap on planes substantially parallel to said first surface and a second phase with a second bandgap which occurs on planes substantially parallel to said third surface and a third bandgap on planes substantially parallel to said fourth surface;
• a second cladding layer doped with receptors for carriers of a second conductivity type and which covers said active region and said groove;
• and
• means for injecting current into said active layer;
• wherein said first and second cladding layers are semiconductor materials having bandgaps different than said first, second,and third bandgaps.