Patent ID: 6546033
Filing Date: 2003-04-08
Classification: B82Y,H01S

Abstract:
A semiconductor laser device comprising:a GaAs substrate of a first conductive type; a lower cladding layer of said first conductive type, formed on said GaAs substrate; a first lower optical waveguide layer made of Inx2Ga1âˆ’x2As1âˆ’y2Py2 having a first bandgap, and formed on said lower cladding layer, where 0&lE;x2&lE;0.3 and x2=0.49y2; an intermediate layer made of Inx5Ga1âˆ’x5P and formed on said first lower optical waveguide layer, where 05<1; a second lower optical waveguide layer made of Inx2Ga1âˆ’x2As1âˆ’y2Py2 having said first bandgap, and formed on said intermediate layer except for near-edge areas of said first intermediate layer located in first vicinities of opposite end facets of said semiconductor laser device so as to leave first portions of spaces in the first vicinities of opposite end facets, where 0&lE;x2&lE;0.3 and x2=0.49y2; a compressive strain active layer made of Inx1Ga1âˆ’x1As1âˆ’y1Py1 having a second bandgap smaller than said first bandgap, and formed on said second lower optical waveguide layer so as to leave second portions of said spaces in second vicinities of opposite end facets, where 01&lE;0.4 and 0&lE;y1&lE;0.1; an upper optical waveguide layer made of Inx2Ga1âˆ’x2As1âˆ’y2Py2 having said first bandgap, and formed on said compressive strain active layer so as to leave third portions of said spaces in third vicinities of opposite end facets, where 0&lE;x2&lE;0.3 and x2=0.49y2; a cap layer made of Inx5Ga1âˆ’x5P and formed on said upper optical waveguide layer so as to leave fourth portions of said spaces in fourth vicinities of opposite end facets, where 05<1; a non-absorbent layer made of Inx6Ga1âˆ’x6As1âˆ’y6Py6 having a third bandgap greater than said second bandgap, and formed over said cap layer so that said spaces are filled with the non-absorbent layer, where 0&lE;x6&lE;0.3 and x6=0.49y6; an upper cladding layer of a second conductive type, formed on said non-absorbent layer; and a contact layer of said second conductive type, formed on said upper cladding layer.