Disclosed is a method wherein light beams emitted from two light sources are combined together and applied to a recording medium and the light beams reflected from the recording medium are drawn out being separated from each other. The method is such that the wavelengths of the light beams from both the light sources are made different from each other, i.e., λ 1 , X 2 , and the light beams from the light sources are combined together by means of a polarization beam splitter, two quarter wave plates, optical filters and so forth and are then simultaneously focussed by a single focussing lens substantially along the optical axis thereof, thereby allowing microspots of light focussed to be disposed on a disc close to each other. Moreover, the light beams reflected from the disc are drawn out being completely separated from each other by the polarization beam splitter owing to the difference in polarization direction. Further, for example, one of the light beams entering the polarization beam splitter is passed through a magnifier prism having a magnifying surface and a reflecting surface, or one or more cylindrical lenses to magnify the beam diameter only in the direction parallel to the composition surface of a semiconductor laser as the light source thereof, so as to be a light beam of substantially circular cross section. On the other hand, the other light beam is passed through one or more cylindrical lenses to reduce the beam diameter only in the direction parallel to the composition surface of a semiconductor laser as the light source thereof so as to be a light beam of oval cross section. Thereby, a substantially circular microspot of light and an oval microspot of light can be obtained on the disc. Furthermore, the two light sources, the polarization beam splitter and a splitter prism are arranged so that the optical axes of the light beams from both the light sources and the optical axis for drawing out the light reflected from the disc and leading the same to the photodetector are made substantially parallel to each other. Thereby, the optical recording and reproducing head is made more compact.