GAIN EQUALIZER AND LIGHT TRANSMISSION SYSTEM

摘要

PROBLEM TO BE SOLVED: To make possible equalizing a gain characteristic of an optical amplifier for a wavelength ranging to a wide wavelength band by providing plural periodic optical filters connected to the optical amplifier and having a transmission characteristic making the wavelength decided based on a wavelength difference between gain peaks a period. SOLUTION: An inputted wavelength multiplex optical signal is amplified by an A1 high density EDFA 10 to be outputted through the optical filter 20 being a gain equalizer. The optical signal in the A1 high density EDFA 10 is amplified by energy supplied from an excitation LD 12. The optical signal supplied to an output terminal is monitored by a photodetector 14, and an excitation LD controller 16 adjusts the output energy of the excitation LD 12 so as to fix the output power of the light signal based on the monitored value. Further, the optical filter 20 is provided with plural optical filters 20-1 to 20-3 connected in series, and equalizes the amplification characteristic of the A1 high density EDFA 10 ranging to the wide band.