<p>An optical information reproducing apparatus of the invention includes a light emitting and receiving unit and an optical system. The optical system converges light from the light emitting and receiving unit on a recording medium and converges the light after reflected by the recording medium. The light emitting and receiving unit includes: a semiconductor laser device disposed an a substrate for generating light; a photo detector formed, integrally with the substrate, on the substrate on which the semiconductor laser device is disposed, for outputting a signal corresponding to the intensity of light incident thereon; and a beam splitter provided on an optical axis of the reflected light, the beam splitter leading part of the reflected light to the photo detector. <IMAGE></p>
