Yokogawa Electric Corporation

Yasukazu Akasaka

Akira Miura

Tsuyoshi Yakihara

Akira Toyama

Morio Wada

Hirotoshi Kodaka

Shinji Kobayashi

Shinji Iio

Chie Sato

Masayuki Suehiro

Katsuya Ikezawa

Daisuke Hayashi

Hiroshi Sugawara

Toshiaki Kobayashi

Sadaharu Oka

Hiroshi Shimizu

Tadashige Fujita

Kenji Uchida

Hiroyuki Matsuura

Makoto Komiyama

Yoshiyuki Asano

Shin-ichi Nakajima

Toshimasa Umezawa

Machio Dobashi

Toshimichi Suzuki

Kousuke Doi

Shoujirou Araki

Hironori Okita

Kanji Tatsumi

Ikurou Aoki

Masamichi Ohashi

Toshiyasu Izawa

Katsutoshi Sakakibara

Yoshihito Sanpei

A clock recovery apparatus for generating a recovery clock from received data may include, but is not limited to, first and second oscillators. The first oscillator generates a first signal having a first frequency. The first signal synchronizes with the received data when the received data has a first level. The second oscillator is connected in series to the first oscillator. The second oscillator generates a second signal as the recovery clock when the first signal has a second level. The second signal has a second frequency. The second signal synchronizes with the first signal.

Clock recovery apparatus

In a light modulating apparatus of an external modulating type which is used in an optical communication system, there are provided an LN modulator, a light branching circuit, a photoelectric converter, a bias control circuit, a driver for an LN modulator which serves to drive the LN modulator in response to an input electric signal, a capacitor for cutting off DC and low frequency components of the input electric signal, a low frequency component compensating circuit for compensating the DC and low frequency components of the input electric signal, and an adding circuit for adding an output of the bias control circuit and that of the low frequency component compensating circuit and generating a bias control signal of the LN modulator.

Light modulating apparatus

Disclosed is a repeater including: a recognizing unit to recognize a destination address of an optical packet from the optical packet which includes the destination address assigned in unit of bit and a bit indicating whether or not a plurality of destination addresses are assigned; an optical splitting unit to split the optical packet into a plurality of optical packets; and selecting units to select transmission channels for the split optical packets on the basis of recognition results by the recognizing units, respectively.

Repeater and optical communication system

An object of this invention is to realize a pulse pattern generating apparatus that outputs a test signal of high waveform quality even when the shape of an eye pattern is changed. This invention is an improvement of a pulse pattern generating apparatus that generates a test signal of a predetermined pattern by using plural digital-analog converters and outputs the test signal to a test subject. The apparatus includes: a parameter setting unit for setting values of plural parameters that determine the shape of an eye pattern of the test signal; a storage unit for storing output values to the digital-analog converters corresponding to the values of the parameters; an arithmetic operation unit for calculating output values to the digital-analog converters from the values of the parameters from the parameter setting unit and the output values in the storage unit; and a voltage value setting unit for setting, for the digital-analog converters, voltage values to be outputted from the digital-analog converters on the basis of the result of calculation by the arithmetic operation unit.

Pulse pattern generating apparatus

There is provided a PD-TIA module that can be used for recognition of an address of an optical packet signal in a system having variation in mark rate all the time, such as an optical packet communication system. An optical communication module comprises a photoelectric converter for converting an optical signal into a current signal, a current/voltage conversion means connected to the photoelectric converter, for converting the current signal into a voltage signal, and a limiting amplifier for receiving and amplifying an electric signal subjected to voltage conversion by the current/voltage conversion means while comparing the electric signal as amplified with a predetermined threshold value, thereby outputting a signal for '0' or '1'.

Optical packet communication device with an applied negative voltage for canceling an offset voltage

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

A photo diode array having improved linearity, wherein a plurality of photo diodes are arranged in an array with a plurality of electrodes connected to both ends of the light receiving surface of each photo diode to obtain current generated in each photo diode.

Photo diode array

Growing community of inventors

Musashino, Japan

Yasukazu Akasaka