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US 6,646,792 B2Granted
Light amplifier and light transmission system using the same
AssigneeNEC Corporation
InventorKeiji Nakamura
Life of this patent
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AssigneeNEC Corporation
InventorKeiji Nakamura
Estimating the term…
An optical output signal of an optical amplifier 1 branched by an optical divider/splitter 2 is separated by an optical demultiplexor 3 into different paths □1 to □n in accordance with the wavelength, and the level of each different wavelength component is adjusted under the control of an optical attenuator control circuit 9 on the basis of a transmission wavelength information notified through a transmission wavelength information input terminal 14. At this time, in the path corresponding to the wavelength transmitted, the attenuation amount of an optical attenuator is controlled to a minimum level, and in the path corresponding to the wavelength other than the wavelength transmitted, the attenuation amount of an optical attenuator is controlled to a maximum level. After the level adjustment, the different wavelength components are combined by an optical multiplexor 5, and the level of the combined signal is detected by a photo diode 6.
A light amplification device which includes a light amplification means for amplifying a wavelength division multiplexing optical signal to output an amplified optical signal, and a branch means for branching a portion of said amplified optical signal to supply a branch signal, and which is so configured that an amplification level of said light amplification means is controlled on the basis of the result of the comparison of the level of said branch signal with a predetermined level,
A light transmission system for transmitting and repeating a wavelength division multiplexing optical signal by light amplification devices connected through a transmission path in a multi-stage structure, said light amplification devices comprising:
Dependencies are inferred from the claim text.