Patent ID: 8477824

Claim:
A semiconductor laser apparatus comprising: a semiconductor laser array stack in which a plurality of semiconductor laser arrays, each semiconductor laser array having a plurality of active layers each of which extends along a first direction on a predetermined plane and which are arranged along a second direction perpendicular to the first direction and in parallel on the predetermined plane, are stacked in a third direction perpendicular to the predetermined plane; a first collimator lens for collimating a plurality of beams emitted from said respective active layers, in the third direction perpendicular to the predetermined plane; a path rotator for outputting each beam arriving from said first collimator lens and collimated in the third direction, with a predetermined divergence angle in the third direction in a state in which a transverse section of the beam is rotated by about 90°; and an optical element arranged at a position where said optical element crosses at least a part of each beam with the predetermined divergence angle in the third direction, outputted from said path rotator, and transmits the rest of the beam, and having a reflecting surface constituting at least a part of an external resonator in cooperation with said active layers, wherein the reflecting surface is so inclined at a predetermined angle relative to a plane perpendicular to an optical axis of each beam outputted from said path rotator, as to totally reflect a part of each arriving beam to return the totally reflected part of each beam to the associated one of said active layers, wherein an angle of installation of the reflecting surface in said optical element is smaller than a half of the divergence angle of each beam outputted from said path rotator.