A semiconductor laser device includes a dielectric multilayer film with a reflectance
of 40% or more, on at least one of optical exit faces of a laser chip. The dielectric
multilayer film includes a film of tantalum oxide (Ta2O5)
and another film of a dielectric oxide, such as aluminum oxide (Al2O3),
and silicon oxide (SiO2). The tantalum oxide film has an optical absorption
coefficient smaller than that of silicon (Si) and thermal stability in emission
superior to that of titanium oxide (TiO2), thereby remarkably improving
the catastrophic optical damage degradation level of the laser chip.