Patent ID: 7542642

Claim:
A multi-beam generating device comprising a plurality of semiconductor lasers, a plurality of optical fibers to propagate laser beams emitted by the semiconductor lasers, an optical fiber array to propagate the laser beams having passed through the optical fibers, and an optical waveguide device provided with a plurality of waveguides to propagate the laser beams having passed through the optical fiber array, wherein each waveguide with a core layer and a clad layer has an input section where a laser beam enters, a curved area in the waveguide, and an output section where the laser beam emits, wherein, in the curved area of the waveguide, a width of the waveguide is narrower in the transverse direction than in the vertical direction, a difference in refractive index is larger in the transverse direction than in the vertical direction, and a pitch between adjacent waveguides in the arrangement of the waveguides is narrower on the output section side than on the input section side, and wherein, at both the input and output sections, the width of the core layer on the outer end side in the transverse direction is identical to that in the vertical direction, the difference in refractive index between the core layer and the clad layer in the transverse direction is identical to that in the vertical direction, and a taper is formed such that the width of the core layer in the transverse direction narrows toward the curved area in the waveguide.