The present invention provides a highly reliable ridge-waveguide semiconductor
laser diode and an optical module. The p-side electrode of the ridge-waveguide
laser diode has a first conductor layer region and a second conductor layer region
formed on the first conductor layer region. At least one of facets of the second
conductor layer region is recessed inward from a reflection facet. Thus, the ridge-waveguide
semiconductor laser diode has a structure in which strain which is caused by the
electrode stress to be applied on the diode facet is reduced and the saturable
absorption does not occur. The ridge-waveguide semiconductor laser diode thus obtained
is highly reliable, and the optical module using the same is remarkably high in reliability.