Dynamic investigation of gain-clamped thulium and erbium-doped fiber amplifiers for reconfigurable WDM systems: comparative study

In this paper, we investigate the gain dynamic of thulium-doped fiber amplifiers TDFAs operating at 2 µm transmission window for a reconfigurable WDM system. A two-level laser model is developed to study the dynamic behaviors of a TDFA and compare to that in an erbium-doped fiber amplifier EDFA operating at 1550 nm transmission window. The power excursion and gain of surviving signal are calculated in 20 reconfigurable WDM channels system. The input signal power of the optical amplifier is varied via add/drop channels in the WDM system with − 17 dBm of each channel power. The simulation results indicate that the gain dynamic of an EDFA is larger than in TDFA due to specific thulium characteristics such a long lifetime of the metastable level and heavily doped concentration. We propose to use the optical gain-clamping OGC technique to restrict any power perturbation of channels reconfiguration. The dynamic performances of a TDFA are more efficient than in EDFA which is important to realize high stability of WDM systems with long-haul transmission systems.