A horizontal cavity semiconductor laser diode comprising: a) a multilayer semiconductor structure made of an Al-containing AlGaAs/GaAs material system, comprising: i) a substrate; ii) at least one lower cladding layer and at least one upper cladding layer having opposite conductivity types and being disposed above the substrate; iii) at least one core layer disposed between the upper cladding layer and the lower cladding layer, wherein a refractive index of the core layer is larger than a refractive index of the lower cladding layer and the upper cladding layer to provide a transverse optical confinement; iv) at least one Al-rich layer with an aluminum composition greater than or equal to 80% embedded into at least one of the lower cladding layer and the upper cladding layer; and v) a highly doped cap layer disposed above the lower cladding layer, and having a conductivity type that is the same as the conductivity type of the upper cladding layer; and b) a ridge comprising a top surface and side walls, wherein the ridge is formed in the multilayer semiconductor structure, and the ridge comprises: i) the cap layer; ii) at least a part of the upper cladding layer; iii) the at least one Al-rich layer, which is partially oxidized from the side walls of the ridge to provide a lateral optical confinement and form an aperture for carrier flow; iv) at least one metal contact disposed on a part of the top surface of the ridge, the metal contact being distanced in a lateral direction from an optical waveguide mode to reduce optical losses; and v) a surface-corrugated grating (171, 172) formed on the top surface of the ridge above an optical waveguide mode. a) a multilayer semiconductor structure made of an Al-containing AlGaAs/GaAs material system, comprising: i) a substrate; ii) at least one lower cladding layer and at least one upper cladding layer having opposite conductivity types and being disposed above the substrate; iii) at least one core layer disposed between the upper cladding layer and the lower cladding layer, wherein a refractive index of the core layer is larger than a refractive index of the lower cladding layer and the upper cladding layer to provide a transverse optical confinement; iv) at least one Al-rich layer with an aluminum composition greater than or equal to 80% embedded into at least one of the lower cladding layer and the upper cladding layer; and v) a highly doped cap layer disposed above the lower cladding layer, and having a conductivity type that is the same as the conductivity type of the upper cladding layer; and i) a substrate; ii) at least one lower cladding layer and at least one upper cladding layer having opposite conductivity types and being disposed above the substrate; iii) at least one core layer disposed between the upper cladding layer and the lower cladding layer, wherein a refractive index of the core layer is larger than a refractive index of the lower cladding layer and the upper cladding layer to provide a transverse optical confinement; iv) at least one Al-rich layer with an aluminum composition greater than or equal to 80% embedded into at least one of the lower cladding layer and the upper cladding layer; and v) a highly doped cap layer disposed above the lower cladding layer, and having a conductivity type that is the same as the conductivity type of the upper cladding layer; and b) a ridge comprising a top surface and side walls, wherein the ridge is formed in the multilayer semiconductor structure, and the ridge comprises: i) the cap layer; ii) at least a part of the upper cladding layer; iii) the at least one Al-rich layer, which is partially oxidized from the side walls of the ridge to provide a lateral optical confinement and form an aperture for carrier flow; iv) at least one metal contact disposed on a part of the top surface of the ridge, the metal contact being distanced in a lateral direction from an optical waveguide mode to reduce optical losses; and v) a surface-corrugated grating (171, 172) formed on the top surface of the ridge above an optical waveguide mode. i) the cap layer; ii) at least a part of the upper cladding layer; iii) the at least one Al-rich layer, which is partially oxidized from the side walls of the ridge to provide a lateral optical confinement and form an aperture for carrier flow; iv) at least one metal contact disposed on a part of the top surface of the ridge, the metal contact being distanced in a lateral direction from an optical waveguide mode to reduce optical losses; and v) a surface-corrugated grating (171, 172) formed on the top surface of the ridge above an optical waveguide mode.