High power semiconductor laser

In a semiconductor laser having a pair of end faces at least one of which is partially transparent to light and comprising a substrate having a pair of opposed major surfaces, with a pair of spaced, substantially parallel grooves in a first major surface with a land therebetween;

• a first confinement layer overlying the first major surface of the substrate and the surfaces of the grooves;
• an active layer overlying the first confinement layer;
• a second confinement layer overlying the active layer;
• and first and second electrical contacts overlying portions of the second confinement layer and the second major surface respectively;
• wherein the substrate and the first confinement layer are of one conductivity type and the second confinement layer is of the opposite conductivity type and wherein the index of refraction of the active layer at the wavelength of light emitted by the laser is greater than that of the first and second confinement layers;
• the improvement which comprises a pair of spaced, substantially parallel anti-guiding regions on both sides of that portion of the second confinement layer over the land and extending a distance through the second confinement layer from a surface thereof towards, but not intersecting, the active layer, and having an index of refraction at said wavelength which is greater than that of the second confinement layer.