Optical amplifier and monitoring method of optical amplifier

摘要

It is object to obtain an optical amplifier which is simple in structure and does not use expensive component parts, while it is capable of evaluating the gain tilt caused by the variation of input light power or temperature and attaining an intended gain tilt. The optical amplifier includes an optical amplification medium which has simultaneous inputs of a WDM signal light and a pumping light and amplifies the WDM signal light, a light source which generates the pumping light, and an amplification characteristic supervisor part which evaluates the gain tilt of amplified signal lights of different wavelengths which form the WDM signal light. The amplification characteristic supervisor part is provided in advance with a record of the relation between the optical amplification medium output light power and the pumping light power corresponding to the output light power in terms of a number of proper curves plotted for certain gain tilts, and adapted to select a proper curve which is nearest to the relation in operation between the power of the pumping light which is incident to the optical amplification medium in operation and the resulting amplified output light power from among the recorded proper curves, thereby determining the gain tilt of the optical amplification medium based on the selected proper curve.