Yokogawa Electric Corporation

Kousuke Doi

Akira Miura

Hiroyuki Matsuura

Akira Toyama

Tsuyoshi Yakihara

Shinji Kobayashi

Kenji Uchida

Hiroshi Sugawara

Toshiaki Kobayashi

Morio Wada

Chie Sato

Katsuya Ikezawa

Hirotoshi Kodaka

Yasukazu Akasaka

Hironori Okita

Ikurou Aoki

Masamichi Ohashi

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

A light modulation apparatus including a Mach-Zehnder type light modulator, a driver for modulator outputting a control signal according to an input electric signal, a light branching circuit branching the output light signal, and a bias control circuit applying a bias voltage to the light modulator based on the branched light signal, the apparatus further comprises: a burst pause state detection circuit detecting a pause state of a burst signal included in the input electric signal; a photoelectric transducer converting an output light signal branched by the light branching circuit into an electric signal; a sampling circuit extracting the electric signal converted while the pause state is detected by the burst pause state; and a bias voltage adjustment circuit adjusting a bias voltage value of the bias voltage based on a voltage level of the extracted electric signal.

Light modulation apparatus and light modulator control method

Growing community of inventors

Musashino, Japan

Kousuke Doi