High-output semiconductor laser element, high-output semiconductor laser apparatus and method of manufacturing the same

A high-output semiconductor laser element comprising a plurality of laser structures, each comprising at least one active layer interposed between a P-type clad layer and a N-type clad layer, which are superposed on a substrate one on another with a P+N+-tunnel junction intervening between each pair of the laser structures,

• the active region of each of the laser structures being not smaller than 10 μm and not larger than 100 μm in width,
• the distance h between the active layers which are most distant from each other in the active layers of the laser structures being not larger than the virtual width W of the active region of the laser element formed by the active regions of the laser structures,
• the width of said semiconductor laser element being not smaller than W+2h, and
• each of the laser structures being provided with at least one of a current-blocking structure and a graded index optical waveguide structure.

A high-output semiconductor laser apparatus comprising

• a semiconductor laser element including a plurality of laser structures which are superposed one on another with a P+N+-tunnel junction intervening between each pair of the laser structures, each of the laser structures comprising at least one active layer interposed between a P-type clad layer and a N-type clad layer and at least two of the laser structures being spaced from each other by a substrate, and
• a pair of heat sinks which are respectively provided on the upper and lower surface of the semiconductor laser element,
• the active region of each of the laser structures being not smaller than 30 μm and not larger than 500 μm in width, and
• the distance between the active layers which are most distant from each other in the active layers of the laser structures being not larger than the virtual width of the active region of the laser element formed by the active regions of the laser structures.