Gain-shifted thulium-doped fibre amplifiers employingnovel high concentration doping technique

Abstract

A novel high thulium concentration doping technique is proposed for shifting the gain band in thulium-doped fibre amplifiers (TDFAs). The gain peak shifts from 1473 to 1505 nm when the Tm3+ concentration is increased from 2000 to 8000 ppm. The authors have achieved gains of > 18 dB and a noise figure (NF) of < 7 dB from 1480 to 1510 nm (30 nm bandwidth) for a total pump power of 500 mW.