A semiconductor laser device of an edge emission type, where a waveguide mode is multi-mode, is provided. The semiconductor laser device includes a first facet of the waveguide on an emission direction front side, the first facet having a first width in a horizontal direction perpendicular to a longitudinal direction of the waveguide; and a second facet of the waveguide on an emission direction rear side, the second facet having the first width, wherein a width of the waveguide, in the horizontal direction, is at least partially narrower than the first width, between the first facet and the second facet.