Gain-switched Tm³⁺-doped double-clad silica fiber laser

A gain-switched Tm-doped double-clad silica fiber laser operating at a wavelength of approximately 2μm with moderate output energy of 14.7mJ per pulse and a slope efficiency of 39.5% (with respect to launched pump energy) is realized pumped at 1.064μm from a Nd:YAG laser. The gain-switched fiber laser pulses are built up by a series of relaxation spikes, and every spike pulse duration is nearly 1μs. The output wavelength becomes longer, and the slope efficiency increases with the increase in fiber length.