Optical head and apparatus for recording and reproducing optical information through the use of the optical head

Abstract

A minute optical head is provided so that a light source and one or more photo detector elements are integrated on the same substrate by a simple manufacturing process and may be applied to an apparatus for recording and reproducing recordable optical information. An apparatus for recording and reproducing optical information is arranged to have a minute optical head. A light waveguide layer composed of column semiconductor crystal is formed on a monocrystalline transparent substrate and an active layer is formed on the side of the light waveguide layer. The light beam source is a semiconductor having a vertical resonator formed of a high-reflection film before and after an emitting surface of the active layer so that a light beam is vertically radiated to the substrate. The photo detector element is integrated on the closer portion of the substrate to the light beam source of the semiconductor laser. Further, on the opposed surface of the substrate to the light beam source are sequentially integrated a first transparent layer, a diffraction grating, a second transparent layer, a phase difference generating element, a third transparent layer, a light beam focusing element, a fourth transparent layer, and a slide-resisting protective layer. The slide-resisting protective layer is located closer to and as opposed to the information recording medium.