Semiconductor laser element and manufacturing method for the same

A semiconductor laser element comprising:

• a clad layer of a first conductivity type;
• an active layer;
• a first clad layer of a second conductivity type;
• a ridge made of a second clad layer of the second conductivity type and a cap layer of the second conductivity type, which are layered on the first clad layer of the second conductivity type, in this order starting from the first clad layer side;
• a dielectric film formed on ridge sides other than a top portion of the ridge;
• and a metal electrode layer that covers the ridge, wherein the width of the bottom of the cap layer and the width of the top surface of the second clad layer are approximately equal;
• wherein the second clad layer is a P type GaAlAs layer and varies a composition ratio of elements in the direction of the thickness and the cap layer is a P type GaAs layer;
• wherein a portion of the second clad layer in contact with the cap layer has an Al composition ratio corresponding to total amount of Al and Ga in the range of 0.38 to 0.46 and has the lowest Al composition ratio in the second clad layer.

A semiconductor laser element comprising:

• a clad layer of a first conductivity type;
• an active layer;
• first clad layer of a second conductivity type;
• a ridge made of a second clad layer of the second conductivity type and a cap layer of the second conductivity type, which are layered on the first clad layer of the second conductivity type, in this order starting from the first clad layer side;
• a dielectric film formed on ridge sides other than a top portion of the ridge;
• and a metal electrode layer that covers the ridge, wherein the second clad layer is a layer of which the composition ratio varies in the direction of the thickness;
• wherein the second clad layer is a P type GaAlAs layer and the cap layer is a P type GaAs layer;
• and
• Al in the second clad layer is included in such a manner that an Al composition ratio corresponding to total amount of Al and Ga varies with a difference of 0.1 or less in a region within ⅓ from the top in the direction of the thickness of the second clad layer.

A semiconductor laser element comprising:

• a clad layer of a first conductivity type;
• an active layer;
• first clad layer of a second conductivity type;
• a ridge made of a second clad layer of the second conductivity type and a cap layer of the second conductivity type, which are layered on the first clad layer of the second conductivity type, in this order starting from the first clad layer side;
• a dielectric film formed on ridge sides other than a top portion of the ridge;
• and a metal electrode layer that covers the ridge, wherein the second clad layer is a layer of which the composition ratio varies in the direction of the thickness;
• wherein the second clad layer is a P type GaAlAs layer and varies a composition ratio of elements in the direction of the thickness and the cap layer is a P type GaAs layer;
• and
• wherein a portion of the second clad layer in contact with the cap layer has an Al composition ratio corresponding to total amount of Al and Ga in the range of 0.31 to 0.46 and has the lowest Al composition ratio in the second clad layer.