Omron Corporation

Masami Tada

Hayami Hosokawa

Noriyoshi Horie

Tsukasa Yamashita

Tatsuo Ohgaki

Hironobu Kiyomoto

Shigeru Aoyama

Tukasa Yamashita

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. Between a semiconductor laser and a collimation lens, there is formed a composite beam splitter having two reflection surfaces. Reflection lights from the magnetooptical disk are respectively reflected by these reflection surfaces and are then received by photosensors. Analyzers are disposed respectively on front sides of the photosensors. The analyzers respectively have polarization directions orthogonal to each other. Each photosensor includes three-partition photodiode. The beam sizing method and the push-pull detection methods are used for detecting the focusing and tracking errors. The optical pickup device can also used to read data from an optical disk. A prism is disposed between a semiconductor laser and a collimation lens. The prism has two reflection surfaces. Reflection lights from a magnetooptical disk are respectively reflected by these reflection surfaces to be received by photosensors. On front sides of the photosensors, there are respectively arranged analyzers respectively having polarization directions orthogonal to each other.

Optical pickup device with substantially mutually orthogonal reflection

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).

Rib optical waveguide and method of manufacturing the same

A grating lens is disclosed in which diffraction efficiency varies in the focusing direction of light on a surface of the lens. Also disclosed is a focusing grating coupler in which the diffraction efficiency of a grating formed on an optical waveguide, which is formed on a substrate, varies in the focusing direction of light.

Grating lens and focusing grating coupler

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Takatsuki, Japan

Masami Tada