Yokogawa Electric Corporation

Fujitsu Corporation

Hirotoshi Kodaka

Akira Miura

Akira Toyama

Hiroshi Sugawara

Shinji Iio

Tsuyoshi Yakihara

Chie Sato

Katsuya Ikezawa

Yasukazu Akasaka

Shinji Kobayashi

Morio Wada

Masayuki Suehiro

Daisuke Hayashi

Hiroki Ooi

George Ishikawa

Hiroyuki Matsuura

Sadaharu Oka

Hiroshi Shimizu

Tadashige Fujita

Daisuke Tanimura

Toshimichi Suzuki

Toshiaki Kobayashi

Yoshiyuki Asano

Shin-ichi Nakajima

Toshimasa Umezawa

Minoru Akutsu

Tetsuya Ohtani

Kousuke Doi

Yusuke Kishine

Hironori Okita

Shigeo Uneme

Kanji Tatsumi

Ikurou Aoki

Masamichi Ohashi

Toshiyasu Izawa

An optical transmission apparatus according to the present invention comprises: a plurality of optical modulating sections serially connected to each other via optical fibers; driving sections corresponding to the optical modulating sections; delay amount varying sections that provide variable delay amounts for modulating signals to be input to the driving sections, to adjust timing between drive signals to be provided for the optical modulating sections; temperature monitoring sections that monitor the temperature of each of the optical fibers and the like; and a delay amount control section that controls the delay amount in each of the delay amount varying sections based on the monitored temperatures.

Optical transmission apparatus

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

A clock reproducing apparatus includes a clock reproducing circuit having: a gated oscillator having an oscillating circuit of two routes; and a frequency control circuit for comparing a phase of an output of the gated oscillator with a phase of a reference clock, and supplying a phase control signal to the gated oscillator based on the comparison result so as to set a delay time, input data is input to a reset input terminal of the gated oscillator, and different route of the two routes of the oscillating circuit operates depending on a case where the input data is 'H' and a case where the input data is 'L'.

Clock reproducing 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

An inspection apparatus inspects an inspected object based on a waveform quality of a signal that the inspected object outputs. The inspection apparatus has a power supply section which outputs a control signal that controls an output of the inspected object, a waveform measuring section which measures the signal that the inspected object outputs to generate a waveform image, an analyzing section which derives a value indicating a waveform quality from the waveform image that the waveform measuring section measures, a deciding section which decides whether or not the value derived by the analyzing section satisfies a target value, and an optimizing section which changes a set value of the control signal that the power supply section outputs, based on a decision result of the deciding section.

Inspection apparatus

The present invention aims at achieving an optical signal processing system which converts a higher speed optical signal to electrical signals by time-demultiplexing the signal with low-speed electrical signals. The present invention offers an improved optical signal processing system that converts a serial pulse train optical signal with transmission speed N to parallel pulse train electrical signals. This system is characterized by providing a serial-parallel converter in which at least two optical switches are cascaded, each of which outputs optical signals with transmission speed M (N&#x3e;M) to one of the two output terminals and outputs the remaining optical signals to the alternative one of said two output terminals by switching connection to said output terminal, receiving parts which convert optical signals from one of the two output terminals of each of the above optical switches to electrical signals, a synchronizing circuit which outputs timing signals in synchronization with electrical signals output from these receiving parts, and drivers which cause the above described optical switches to switch their connections based on timing signals output from the above synchronizing circuit.

Optical signal processing system

Growing community of inventors

Musashino, Japan

Hirotoshi Kodaka