Study on the gain excursion and tilt compensation for 1.4- and 1.5-mu m dual wavelength pumped TDFA

Abstract

In this letter, we analyze the gain excursion and tilt function of the thulium doped fiber amplifiers (TDFAs) for the 1.4- and 1.5-mum dual-wavelength pump approach. We also reveal that those two pump wavelengths act as independent control factors for gain level and tilt function, because each pumps influence the populations of the first and second excited states (H-3(4)-F-3(4)) in a different manner. Gain excursion and gain tilt control of the TDFAs under the channel add-drop situations are demonstrated, revealing a suitable approach and inner dynamics of the gain/tilt excursion and compensation mechanisms for TDFAs.