An optical pickup has a light-emitting device having a first light emitter
and a second light emitter which emit a first laser beam and a second
laser beam, respectively, a beam splitter plate, a collimator lens which
converts the first laser beam and the second laser beam into a parallel
beam, and a light-detecting device. The first laser beam has an optical
axis aligned with an optical axis of an objective lens, and the second
laser beam has an optical axis displaced off the optical axis of the
objective lens. The second light emitter is placed in a position where
the angle .alpha. of incidence of the second laser beam on the beam
splitter plate is greater than the angle .theta. of incidence of the
first laser beam on the beam splitter plate, thereby reducing the amount
of generated aberrations for increased performance.