A semiconductor laser apparatus capable of reducing a spread angle of
emission light with downsizing has an active region between first and
second end surfaces. A first reflection structure and a partial
reflection structure are provided on the first end surface side. The end
surface of the active region is divided into a total reflection region
and a partial reflection region in combination with the first reflection
structure and partial reflection structure. A laser resonator includes
the first reflection structure and partial reflection structure. A second
reflection structure is positioned on the way of a resonance optical path
of the laser resonator. Light emitted within the active region propagates
on a resonance optical path. An induction emission is produced. The
semiconductor laser carries out a laser oscillation. Of the light
arriving at the partial reflection structure, the portion transmitted
through the partial reflection structure is outputted outside the
apparatus.