Theoretical studies on the gain characteristics for 1064-nm pumped thulium-doped fiber amplifier

A group of equations deduced from thulium-doped fiber amplifier (TDFA) rate equations and light propagation equations, introducing the overlapping factors between the (pump and signal) light intensities and the thulium dopant distributions inside the fiber core, is presented in this paper. Using the group of equations, the small signal gain and optimum fiber length and threshold pump power characteristics ofthe amplifier are simulated.