Thulium-doped tellurite fiber amplifier

Gain in the S-band is demonstrated in a thulium-doped tellurite fiber amplifier using dual pump and bidirectional pumping schemes. Two pump schemes were employed: 795/1064 and 1047/1550 nm. The gain profile is broader than achieved in a fluoride fiber and overlaps with the C-band of the erbium-doped fiber amplifier. We reach a fiber-to-fiber gain of 11 dB and an internal gain of 35 dB.