Yokogawa Electric Corporation

Machio Dobashi

Akira Miura

Morio Wada

Shinji Iio

Tsuyoshi Yakihara

Shinji Kobayashi

Chie Sato

Sadaharu Oka

Masayuki Suehiro

Katsuya Ikezawa

Shoujirou Araki

Daisuke Hayashi

Takahiro Kudo

Takashi Mogi

Yoshiyuki Asano

Yasukazu Akasaka

Shin-ichi Nakajima

Toshimasa Umezawa

An optical waveform shaping device includes a first waveguide portion, formed on a substrate, for transmitting the optical signal and simultaneously absorbing a portion of the optical signal, which has a signal level equal to or smaller than a predetermined value, so as to shape the optical signal; and a second waveguide portion, formed on the substrate, for transmitting the optical signal, which was transmitted through the first waveguide portion, and simultaneously amplifying the optical signal. The first waveguide portion may be formed using a saturable absorber. A first electrode for supplying electric current to the first waveguide portion so that the first waveguide portion is provided with a function of absorbing the optical signal; and a second electrode for supplying electric current to the second waveguide portion so that the second waveguide portion is provided with a function of amplifying the optical signal may also be provided.

Optical waveform shaping device including portions for respectively absorbing and amplifying transmitted optical signal

An optical logic device performs a logic operation on a plurality of input light signals. The optical logic device has a photoelectric conversion portion, in which photoreceivers for receiving input light signals are provided in parallel, that outputs an electric signal obtained by adding up outputs of the photoreceivers, and a comparator that compares a voltage level of the electric signal outputted from the photoelectric conversion portion with a predetermined voltage level.

Optical logic device responsive to pulsed signals

In an optical switch, a carrier-accumulating layer in which injected carriers are accumulated is provided on a semiconductor substrate having a waveguide formed thereon so that injected effective carriers tend to be accumulated in an effective part, and the burden on a driving circuit is thus reduced to realize high-speed operation. At the same time, when a clad on the carrier injection side, of clad layers formed on both sides of the waveguide, is a second clad layer, and a clad on the substrate side is a first clad layer, a third clad layer is formed on the first clad layer to reduce propagation loss in the waveguide.

Optical switch

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Tokyo, Japan

Machio Dobashi