Transient gain behavior in 1050/1550-nm dual-wavelength pumped TDFAs

We present an experimental study on transient events in 1050/1550-nm dual-wavelength pumped thulium-doped fiber amplifiers (TDFAs)-a promising candidate for S-band telecommunication applications. For appropriate power ratios of the two pump wavelengths, transient excursions due to signal add-drop are comparable to those in single-wavelength pumped TDFAs. Pump modulation effects, however, more severely impact the signal gain. With our experimental results, it should be possible to develop transient gain suppression control loops for this TDFA type.