Semiconductor laser device and manufacturing method thereof

A semiconductor laser device, comprising:

• an n-type clad layer;
• a first p-type clad layer;
• a ridge stripe including a second p-type clad layer formed into a ridge stripe shape on the opposite surface of the first p-type clad layer from the n-type clad layer;
• an n-side guide layer and a p-side guide layer which are interposed between the n-type clad layer and the first p-type clad layer;
• an active layer interposed between the n-side guide layer and the p-side guide layer;
• and
• a current-blocking layer formed on side surfaces of the ridge stripe,
• wherein a first ridge width of a surface of the second p-type clad layer existing on the same side as the first p-type clad layers is greater than or equal to 3.0 μm and less than or equal to 4.5 μm, and a second ridge width of a surface of the second p-type clad layer existing at the opposite side from the first p-type clad layer is greater than or equal to 2.0 μm,
• wherein the n-type clad layer, the first p-type clad layer and the second p-type clad layer are formed of a (Alx1Ga(1-x1))0.51In0.49P layer that has a composition where x1>0.7, and
• wherein the n-side guide layer and the p-side guide layer is formed of a Alx2Ga(1-x2)As layer that has a composition where 0.4≦x2≦0.8.

A method for manufacturing a semiconductor laser device, the method comprising:

• forming an n-type clad layer;
• forming a first p-type clad layer;
• forming a ridge stripe including a second p-type clad layer formed into a ridge stripe shape on the opposite surface of the first p-type clad layer from the n-type clad layer;
• forming an n-side guide layer and a p-side guide layer which are interposed between the n-type clad layer and the first p-type clad layer;
• forming an active layer interposed between the n-side guide layer and the p-side guide layer;
• and
• forming a current-blocking layer formed on side surfaces of the ridge stripe,
• wherein a first ridge width of a surface of the second p-type clad layer existing on the same side as the first p-type clad layers is greater than or equal to 3.0 μm and less than or equal to 4.5 μm, and a second ridge width of a surface of the second p-type clad layer existing at the opposite side from the first p-type clad layer is greater than or equal to 2.0 μm,
• wherein the n-type clad layer, the first p-type clad layer and the second p-type clad layer are formed of a (Alx1Ga(1-x1))0.51In0.49P layer that has a composition where x1>0.7, and
• wherein the n-side guide layer and the p-side guide layer is formed of a Alx2Ga(1-x2)As layer that has a composition where 0.4≦x2≦0.8.