Patent ID: 7424044

Claim:
A semiconductor laser device that includes a semiconductor laser array having a plurality of active layers, while setting a first direction to an optical axis direction, a second direction to a slow axis direction, and a third direction to a fast axis direction, arranged in parallel along the second direction and outputs laser beams from a front end face side of the active layers, comprising: a collimating lens that collimates laser beams outputted from respective rear end faces of the active layers within a plane orthogonal to the second direction; and a first optical element that feeds back respective parts of laser beams outputted from the collimating lens to the respective active layers via the collimating lens, wherein the first optical element is a stripe mirror having transmitting portions and reflecting portions which are alternately arranged in the second direction, wherein the reflecting portions of the stripe mirror are disposed corresponding to the positions of the respective active layers of the semiconductor laser array, wherein the respective reflecting portions of the stripe mirror and the front end face side of the respective active layers are configured so that they form an external resonator that makes laser beams reciprocate between the respective reflecting portions of the stripe mirror and the front end face side of the respective active layers, and wherein the transmitting portions of the stripe mirror transmit a laser light which is emitted from the collimating lens in a direction backward of the stripe mirror so that the transmitted laser light does not contribute to the external resonation.