Abstract: An integrated optical pickup device for a magnetooptical recording medium (e.g. a magnetooptical recording disk) and/or an optical recording medium (e.g. an optical recording disk) in which a plurality of focusing grating couplers are formed on an optical waveguide layer manufactured on a substrate. A light reflected from a magnetooptical disk or an optical disk is guided by the focusing grating couplers into the waveguide layer to be separated and to be converged therethtough. The converged lights are detected so as to produce a tracking error signal, a focusing error signal, and an information readout signal. The plural focusing grating couplers are fabricated at an identical location on the waveguide in a superimposed fashion. This increases the utilization efficiency of reflection light per each unitary area of the focusing grating couplers and hence the signals are obtained in a stable state.

Abstract: An optical read/write head for a magnetic-optic recording and reproducing unit having a beam splitter placed between a collimator lens and an objective lens. The optical path of the beam reflected by a recording disk is bent by the beam splitter and the beam strikes a polarizing beam splitter. The polarizing beam splitter splits the reflected beam into P and S polarized components whose optical axes form n angel of less than 90.degree.. The rays of the P and S polarized components strike respective light detecting elements and which are co-arranged on substantially the same surface.

Abstract: On a substrate (1), a core layer (2) is formed such that the core layer (2) includes a rib section (2a) fabricated to be integral therewith. The core layer (2) and the rib section (2a) are formed with a liquid material to be solidified under an energy irradiation, for example, a UV-setting resin. A clad layer (3) is disposed on the core layer (2). A buffer layer (4) is formed between the core layer (2) and the substrate (1).

Abstract: An optical read/write head for a magnetic-optic recording and reproducing unit having a beam splitter placed between a collimator lens and an objective lens. The optical path of the beam reflected by a recording disk is bent by the beam splitter and the beam strikes a polarizing beam splitter. The polarizing beam splitter splits the reflected beam into P and S polarized components whose optical axes form n angel of less than 90.degree.. The rays of the P and S polarized components strike respective light detecting elements and which are co-arranged on substantially the same surface.

Abstract: On a substrate (1), a core layer (2) is formed such that the core layer (2) includes a rib section (2a) fabricated to be integral therewith. The core layer (2) and the rib section (2a) are formed with a liquid material to be solidified under an energy irradiation, for example, a UV-setting resin. A clad layer (3) is disposed on the core layer (2). A buffer layer (4) is formed between the core layer (2) and the substrate (1).

Abstract: An optical element having a substrate and a composite grating pattern formed thereon. The pattern is constituted with two different kinds of grating patterns superimposed on the substrate. When one of the two kinds of grating patterns is formed in a Fresnel lens pattern, a light focusing or collimating function (i.e. a lens function) is implemented. When the other pattern is formed in an equally separated linear grating pattern, the optical element develops the lens function and a function to diffract lights through the linear grating. When one of the two kinds of grating patterns is formed in a Fresnel lens pattern and the other pattern is implemented in an unequally separated linear grating pattern, a lens function to focus lights onto a point and a cylindrical lens function to focus lights in a linear contour are obtained. Consequently, when parallel lights are incident to the optical element, there occurs astigmatism.