A semiconductor laser device includes a substrate which is made of, e.g.,
silicon and which has in its principal surface first and second recessed
portions formed at a distance from each other. Disposed in the first
recessed portion is a first semiconductor laser chip in the form of a
function block, which emits an infrared laser beam. Disposed in the
second recessed portion is a second semiconductor laser chip in the form
of a function block, which emits a red laser beam.