A recorded data reader is provided with a light source for emitting a beam of light and with a photosensitive means. A polarized beam splitter incorporates an interface developed between a titanium diffused region and a proton exchanged region, formed by treating one region of a titanium diffused layer for proton exchange. Both regions are arranged on a substrate of lithium niobate material. Also, a collimator lens, a surface wave electrode, and a grating lens are embedded in the same substrate, thus forming a transmitting and separating arrangement, which transmits the light beam emitted by the light source and which separates a return beam of light originating from a recording medium.