Noise and gain band management of thulium-doped fiber amplifier with dual-wavelength pumping schemes

Three dual-wavelength pumping schemes (1550 nm + 1064, 1047, or 1400 nm) have been experimentally assessed for the thulium-doped fiber amplifier in terms of power and noise performance. It is shown that 1047- and 1550-nm pumping gives a better power performance than 1064- and 1550-nm pumping at fixed gain peak wavelength (GPW). In addition, the most efficient pumping scheme appears to be 1400- and 1550-nm pumping for GPW higher than 1475 nm, and 1047 and 1550 nm for lower GPW. Noise figures lower than 6 db (with -5-dBm signal input power) are exhibited regardless the pumping schemes (although a 0.8-dB increase is reported for the 1400- and 1550-nm pumping).