Semiconductor laser device with a sulfur-containing film provided between the facet and the protective film

In a semiconductor laser device which emits laser light from a facet, comprising a multi-layered structure including a pair of electrodes and formed on a semiconductor substrate, said multi-layered structure having an AlGaAs active layer for laser oscillation, and a protective film formed on said facet of said multi-layered structure, the device wherein a film containing sulfur is provided between the facet and the protective film so as to be formed directly on said facet;

• and wherein said sulfur-containing film consists essentially of chemical elements selected from the group consisting of gallium, aluminum, arsenic, nitrogen, hydrogen, and sodium, in addition to a sulfide of AlGaAs.