Semiconductor laser device, astigmatic correction plate used therefor and method of arranging the astigmatic correction plate

摘要

Provided are a semiconductor laser device capable of increasing an emission angle of a laser beam, an astigmatic correction plate used therefor and a method of arranging the astigmatic correction plate. In order to correct astigmatism of a laser beam emitted from a first laser light source or a second laser light source, the astigmatic correction plate is arranged so as to diagonally intersect an optical center line (an optical axis) of the laser beam, and the astigmatic correction plate, the first light source and the second light source are arranged so that an optical axis of the first laser light source coincides with a center line (CL) of an effective diameter of an aperture and a distance from the second laser light source to the astigmatic correction plate in a direction parallel to the optical axis is shorter than a distance from the first laser light source to the astigmatic correction plate.