EVALUATION METHOD OF OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To provide an evaluation method of an optical fiber capable of performing accurate substantial gain-absorption measurement in an erbium/ytterbium doped fiber (EYDF) and capable of estimating a gain coefficient spectrum of EYDF while using an EDFA component.SOLUTION: The evaluation method of the optical fiber is configured to evaluate an EYDF 6 in a device including an optical amplifier including a semiconductor layer 1 for supplying signal light, an excitation light laser 2 for supplying excitation light, a multiplexer 3 and an optical isolator 4. The method includes: measuring a loss of an optical component in an input part and an output part of the optical amplifier; calculating a correspondence between excitation light power and a gain by measuring a small signal gain while varying the excitation light power by using the excitation light ofIlevel excitation for the EYDF subjected to the evaluation; calculatingεfrom the calculated correspondence between the excitation light power and the gain; calculating an absorption loss coefficient spectrumα(νs) of the EYDF subjected to the evaluation; and calculating a gain coefficient g*(ν) of the EYDF subjected to the evaluation from theεandα(νs).