OPTICAL DIRECT AMPLIFICATION SYSTEM

Japanese Patent JPH04293025

A

PURPOSE:To eliminate the need to equip each optical amplifying circuit with a demultiplexer and cause no decrease in gain, to eliminate the need for photoelectric conversion, and to make the circuit constitution simple and small in size and improve the reliability and transmission characteristics by detecting a fed current from varying and performing control gain in each optical amplifying circuit which varies the fed current corresponding to variation in the reception level of a pilot signal at a terminal station. CONSTITUTION:This system is equipped with a transmitting terminal station 12A which sends a light signal, generated by superposing a pilot signal upon a sent signal, to a transmission line 14, a receiving terminal station 12B having a feeding device 15B which varies the current fed to the optical transmission line 14 corresponding to the level variation of the pilot signal, a driving circuit which is arranged halfway on the optical transmission line 14 and sets the level of a light signal for excitation corresponding to the level of the fed current, and an optical fiber amplifying circuit 13 having a light emitting element which sends the light signal for excitation in response to the current signal and an optical fiber amplifier which amplifies the received light signal from the optical transmission line corresponding to the light signal for excitation and sends it out to the optical transmission line.

ENOMOTO TORU

JP5753191A

October 16, 1992

March 22, 1991

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NEC CORP

G02F1/35; H01S3/06; H01S3/067; H01S3/07; H01S3/10; H04B10/07; H04B10/29; H04B10/293; H04B10/80; (IPC1-7): G02F1/35; H01S3/07; H04B9/00

Naoki Kyomoto (2 outside)

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