2.8 μm pulsed Er3+:ZBLAN fiber laser based on external gain modulation

Abstract

We report the generation of stable pulses in a ∼2.8 μm Er3+:ZBLAN fiber laser by varying the population inversion of active ions with an external 1973 nm auxiliary pump source. When we increase the 976 nm master pump power to beyond the chaotic self-pulsing stage, stable pulse trains can be obtained immediately with the switch-on of the 1973 nm auxiliary pump source. The pulse repetition rate can be tuned from 22.47 kHz to 63.98 kHz by adjusting the 1973 nm pump power, and the corresponding pulse width is varied from 4.47 μs to 1.99 μs. The underlying mechanism of the pulsed Er3+:ZBLAN fiber laser with external gain modulation is also discussed.