Abstract: Disclosed is a process for forming a polarization inversion layer which can form a periodic metal pattern on one major surface of a substrate and can easily form a fine periodic domain inversion structure. According to this process for forming polarization inversion layer, before or after the step of forming a three-dimensional waveguide, plural pairs of ground anodes and voltage-applying cathodes are formed at predetermined intervals, each pair sandwiching the three-dimensional waveguide along the extending direction thereof, facing each other, and set apart from each other, on one major surface of the substrate parallel to an axial direction where polarization inversion easily occurs, an electron beam is irradiated to the cathodes with the anodes grounded to thereby form a plurality of polarization inversion layers along the extending direction of the three-dimensional waveguide.

Abstract: A polarized beam splitter is provided for transmitting a beam of linearly polarized light vibrating in a predetermined plane. A titanium diffused layer is developed on the lithium niobate substrate and then, a portion of the same is treated by proton exchange thus forming a proton exchanged region. The boundary surface between the titanium diffused and proton exchanged regions is used as a polarizing plane allowing an incoming polarized light vibrating in the predetermined plane to pass through and a polarized light vibrating at a right angle to the plane to reflect.

Abstract: 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.

Abstract: A thin film magnetic recording/reproducing head and a method of manufacturing same. The head is formed by sandwiching a multilayer thin film core between a pair of substrates, and removing a certain amount of the multilayer structure in the regions of the head which define the contact surface and the operational gap. The resulting structure has a thin film core which is thinner at the front core portion than is the back core portion. The method allows better alignment of two halves of the core portion in the vicinity of the operational gap.

Abstract: A composite magnetic material and a magnetic head made from this composite magnetic material formed of a combination of a body of a magnetic metal material and a magnetic oxide material joined together in such a manner as to provide improved strength while attaining an improved manufacturability and regenerative sensitivity at high frequencies. In accordance with the invention, the two bodies are joined together with a thin magnetic metal film initially formed on the oxide material body by vapor deposition or sputtering. The thin magnetic metal film can be made of the same material as the magnetic metal material body.