A semiconductor laser device includes a layer structure of a first
conductive cladding layer, an active layer, and a second conductive
cladding layer sequentially grown on a first conductive semiconductor
substrate; and a light emitting facet from which a laser beam having a
first wavelength is emitted. Refractive indexes of the first and the
second conductive cladding layers with respect to the first wavelength
are lower than an effective refractive index with respect to the first
wavelength. With respect to a light having a second wavelength incident
on the light emitting facet from outside, the refractive index of at
least one of the first and the second conductive cladding layers is equal
to or higher than the effective refractive index with respect to the
second wavelength.