Yokogawa Electric Corporation

Mamoru Hihara

Morio Wada

Shinji Iio

Shinji Kobayashi

Akira Miura

Tsuyoshi Yakihara

Chie Sato

Sadaharu Oka

Masayuki Suehiro

Katsuya Ikezawa

Daisuke Hayashi

Shinichi Nakajima

Yoshiyuki Asano

Yasuyuki Suzuki

Yoshihiro Sanpei

Shin-ichi Nakajima

Koki Iemura

Naoaki Machida

An interferometer of the invention includes: a first splitting element which includes a first transparent medium and a first splitting film formed on the first transparent medium, and which splits incident light into a first split beam and a second split beam, the first split beam being the incident light reflected by the first splitting element and the second split beam being the incident light transmitted through the first splitting element; and a second splitting element which includes a second transparent medium and a second splitting film formed on the second transparent medium, and which causes interference between the first split beam and the second split beam passed through different optical paths, the second splitting element being positioned such that a positional relationship between the second transparent medium and the second splitting film with respect to a direction of incidence on the second splitting element of the first split beam is opposite to a positional relationship between the first transparent medium and the first splitting film with respect to a direction of incidence of the incident light on the first splitting element.

Interferometer, demodulator, and splitting element

An optical packet network system of a ring type, capable of preventing degradation of an optical signal, can be implemented by providing a mechanism relatively simple in structure, capable of erasing light noise if the optical packet signal does not exists. In the optical packet network system made up by interconnecting respective nodes adjacent to each other, and connecting a sending source of an optical packet signal to a ring, a light noise removal function block is provided between the respective nodes adjacent to each other.

Optical packet network system

An optical communication apparatus includes an erbium-doped optical fiber amplifier for amplifying a modulated optical signal, wherein a light which is not modulated is inputted to the erbium-doped optical fiber amplifier together with the optical signal.

Optical communication apparatus

An optical switch changes over transmission paths of an optical signal by a refractive index change. The optical switch has an optical waveguide layer having an optical waveguide whose output path of an optical signal branches into two, and reflection diffusing ditches which are provided in a portion outside the optical waveguide in the optical waveguide layer, wherein the portion is closed to a branch portion of the optical waveguides. The reflection diffusing ditches extend in a direction crossing a traveling direction of the optical signal.

Optical switch

Growing community of inventors

Tokyo, Japan

Mamoru Hihara