In a laser light multiplexing apparatus: a collimating optical system collimates
light beams emitted from semiconductor lasers so that the slow axes of the light
beams become coplanar, and optical axes of the light beams become parallel to each
other; a light beam rearrangement optical system constituted by prisms respectively
arranged in correspondence with the light beams rearranges the light beams in such
a manner that directions of the fast axes of the light beams are changed at different
locations along a direction in which the light beams propagate, and the fast axes
of the light beams become coplanar; and a convergence optical system converges
a bundle of the light beams rearranged by the light beam rearrangement optical
system, in directions of the fast axes and the slow axes of the light beams, and
makes the converged bundle of the light beams enter an optical fiber.
