Yokogawa Electric Corporation

Moritoshi Komamaki

Yoshinori Matsumoto

A fiber measurement device includes: a light detector adapted to detect feedback light of laser light output to a fiber; a band limiting circuit adapted to extract, from a signal depending on the feedback light, a signal having a component corresponding to a frequency of the laser light, wherein the signal extracted by the band limiting circuit is a first differentiation target signal; and a waveform equalizing circuit having a differentiating and adding circuit adapted to differentiate the first differentiation target signal to generate a first differentiation result signal and to add the first differentiation target signal and the first differentiation result signal.

Fiber measurement device

There is provided a light pulse generator. The light pulse generator includes: a laser diode; a voltage source that provides a bias voltage to the laser diode; a switching element that causes the laser diode to emit a light pulse by directly modulating the laser diode; and an auxiliary current circuit which starts to charge immediately after turn-on of the switching element and which starts to discharge after a forward current flows through the laser diode so as to provide a auxiliary current to the laser diode in the same direction as the forward current.

Light pulse generator and optical time domain reflectometer using the same

An optical pulse generator includes a light emitting element that emits an optical pulse, and a driver. The driver is configured to apply a pulse driving current to the light emitting element to allow the light emitting element to emit an optical pulse. The driver is also configured to apply a preliminary driving current to the light emitting element prior to starting the application of the pulse driving current. The preliminary driving current is lower than a minimum level that needs to cause a stimulated emission of light.

Optical pulse generator and optical pulse tester

A switching power supply causes fewer losses, being capable of suppressing surges generated at a switching element, and providing improved conduction noise characteristics. The present invention is a switching power supply, wherein voltages and currents are varied by turning said switching element on and off to convert input voltages into output voltages, comprising a distributed parameter line with a line length of about(n is an integer of one or more) of a wavelength peculiar to a potential point at said fluctuating potential point in said switching power supply.

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Tokyo, Japan

Moritoshi Komamaki