Mode-Locked Ho3+-Doped ZBLAN Fiber Laser at 1.2 μm

A mode-locked Ho
³⁺
-doped ZBLAN fiber laser at 1.2 μm was demonstrated for the first time employing a nonlinear polarization rotation technique for mode-locking. The laser was pumped at 1137 nm by the Raman fiber laser. Stable dissipative soliton mode-locking was achieved with an intracavity Lyot filter formed from a length of polarization maintaining fiber and a polarization dependent optical isolator. 1.3-nJ pulses with pulse duration of 47 ps at a repetition rate of 1.77 MHz were produced. Multiple pulse operation with burst energy up to 6.7 nJ was observed at higher pump power.