Included are a plurality of cylindrical holders having holes into which laser modules are fitted and fixed, respectively; a plate-like base that has a first surface, a second surface opposite to the first surface, and a plurality of through holes through which the laser beams from the plurality of laser modules fixed to the holder pass, the holders abutting against the first surface so as to connect the holes thereof to the through holes of the base, the second surface of the base being arranged with a plurality of lenses corresponding to the through holes; and adhesives applied to outer corners of abutment portions, at which the base and the LD holders abut against each other, for fixing the base and the LD holders to each other.