Performance evaluation of S-band Thulium doped silica fiber amplifier employing multiple pumping schemes

Gain of Silica Thulium doped fiber amplifier (TDFA) is limited due to high phonon energy of Thulium ions. In this paper the gain performance of Silica based TDFA has been compared for 1050 nm, 1050 nm + 800 nm, 1050 nm + 1400 nm and1050 nm + 1400 nm + 800 nm pumping schemes. The gain enhancement of 6.5 dB in triple pumping scheme (1050 nm + 1400 nm + 800 nm) as compared to dual pumping (1050 nm + 1400 nm) and 14.5 dB enhancement than the 1050 nm single pump has been observed. In the wavelength region 1455 nm-1490 nm, the observed gain triple pumping is more than 20 dB with noise figure less than 5 dB, the maximum gain obtained is 26.5 dB at 1470 nm.