GAIN FLATTENED OPTICAL FIBER AMPLIFIER

摘要

PURPOSE: An gain flattened optical fiber amplifier is provided to be capable of adjusting the length of an erbium doped fiber by measuring a characteristic of each fiber using an optical coupler for separating a predetermined light signal. CONSTITUTION: The first and second isolators(200, 250) prevent an amplification efficiency of each erbium doped fiber(EDF) from being dropped by the reflecting of an amplified signal. A wavelength selective coupler(WSC)(220) couples a pumping light signal having a 980nm wavelength from a pumping light source(210) and an input light signal of a 1550nm wavelength from an input stage, and transfers the coupled signal to a single light transfer path. The first erbium doped fiber amplification measuring part(230) has the first coupler(232), the first EDF(233) and the second coupler(234), and measures a backward amplified spontaneous emission(ASE) by EDF of the first EDF(233) and the second erbium doped fiber amplification measuring part and a characteristic of an erbium doped fiber amplification considering only the first EDF(233). The second erbium doped fiber amplification measuring part(240) has the third coupler(242), and the second EDF(233) having a different gain characteristic from the first EDF(233), and measures an amplified spontaneous emission(ASE) by EDF of the second EDF(243) and a characteristic of an erbium doped fiber amplification considering only the second EDF(243).