Ricoh Company, Ltd.

Syunsuke Fujita

Magane Aoki

Shigeyoshi Misawa

Tami Isobe

Kiyoshi Yokomori

Hiroyoshi Funato

Yoshinobu Nakayama

An apparatus for recording and reproducing optical information includes an optical integration detecting element arranged on an optical path of light from a laser beam source to an optical information recording medium. The optical integration detecting element has an optical waveguide layer formed on a substrate; a photodetector connected to the optical waveguide layer; a first gap layer formed on the optical waveguide layer and having a refractive index lower than that of the optical waveguide layer; a second gap layer formed on the first gap layer and having an opening portion and a refractive index lower than that of the optical waveguide layer; an adhesive layer having a refractive index higher than that of the optical waveguide layer and adhered to the first gap layer such that the opening portion of the second gap layer is filled with the adhesive layer; and a prism adhesively fixed to an upper portion of the adhesive layer and constructed by a dielectric substance having a refractive index higher than that of the optical waveguide layer.

Apparatus for recording and reproducing optical information and prism

A magneto-optical signal detection device comprising a thin film type optical waveguide unit having a substrate on which a waveguide is formed. The unit has a coupling portion for coupling two polarization components simultaneously in a same plane of the waveguide as a TE mode and a TM mode. The modes TE and TM are included in reflection light reflected from a magneto-optical recording medium and perpendicular to each other. The unit also has a TE-TM mode separating portion having a taper boundary. A waveguide layer is gradually thinned in the taper boundary toward an outer end thereof.

Mode splitter and magneto-optical signal detection device

A high efficiency prism coupling device that comprises a substrate, an optical waveguide layer disposed on the substrate, a gap adjuster layer disposed on the waveguide layer and a prism secured to the gap adjuster layer through a dielectric adhesive agent. The gap adjuster layer has a refractive index which is lower than that of the waveguide layer. The gap adjuster layer has a recess formed therein for guiding an incident beam to the waveguide layer through a bottom portion thereof. The adhesive agent is disposed in and around the recess and has a refractive index which is higher than that of the waveguide layer. The prism is made from a dielectric material and disposed above the recess of the gap adjuster layer through the adhesive agent. The prism has a refractive index which is higher than that of the waveguide layer. The incident beam is introduced from outside through the prism, the adhesive agent and the bottom portion of the recess to the waveguide layer.

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Yokohama, Japan

Syunsuke Fujita