Nec Corporation

Nec Laboratories America, Inc.

Katsuyuki Mino

Ting Wang

Osamu Matsuda

Takefumi Oguma

Lei Zong

An optical amplifier control apparatus according to the present invention includes control circuit; optical amplifiersrespectively located on paths; a plurality of light sourcesthat output excitation lights that differ in light intensity; and optical switchthat changes optical routes of excitation lights that are output from light sourcesand inputs the excitation lights to optical amplifiersas determined by control circuit. Control circuitis provided with determination sectionthat determines which paths to allocate which excitation lights that differ in light intensity based on a parameter that relates to wavelength lights on a plurality of paths when wavelength lights of WDM signal light that propagate to one of the plurality of paths are optically amplified.

Optical amplifier control apparatus

An optical amplifier of the present invention includes: an optical amplifier circuit that amplifies input signal light and outputs the amplified light as output signal light; a first monitor for monitoring the presence or absence of the input signal light; and a control circuit that, when receiving a shutdown control signal, controls the optical amplifier circuit such that a shutdown control speed for reducing a level of the output signal light to zero differs according to the presence or absence of the input signal light.

Optical amplifier

Methods and systems for controlling power fluctuations in a network including a plurality of nodes are disclosed. A node in the network may be configured to modify power levels in accordance with either an active state or an inactive state. The node may transition to an inactive state in response to a power change that exceeds a power change threshold. The role of the node in controlling the power fluctuation in the network is reduced in the inactive state.

Method and system for power stability control in wavelength division multiplexing networks

An optical amplifier includes a detecting section configured to detect a part of an input optical signal from a first node on an input side optical fiber; and a rare earth element doped optical fiber amplifier configured to amplify a remaining part of the input optical signal supplied from the input side optical fiber by using an excitation optical signal supplied from a second node and to output the amplified optical signal as an output optical signal to an output side optical fiber. A control unit controls the excitation optical signal based on the detected part of the input optical signal by the detecting section without real time control based on the output optical signal.

Optical amplifier, optical amplifier controller and control method of the same

An optical transmission apparatus includes a transmitting unit for transmitting an optical signal with a specified wavelength, a multiplexing unit for multiplexing the optical signal with the specified wavelength and an optical signal with a wavelength other than the specified wavelength and outputting the multiplexed signal as a wavelength division multiplexed optical signal, an optical amplifier for amplifying the wavelength division multiplexed optical signal outputted from the multiplexing unit, a level detecting unit detecting a variation of an optical power of the wavelength division multiplexed optical signal inputted to the optical amplifier, and a level adjusting unit for adjusting, when a variation of the optical power of the wavelength division multiplexed optical signal is detected by the level detecting unit, a transmitting power of the optical signal with the specified wavelength transmitted from the transmitting unit so that an output power becomes a level before the variation.

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Tokyo, Japan

Katsuyuki Mino