High Peak-Power Gain-Switched Tm $^{3+}$-Doped Fiber Laser

Resonantly pumped by a 1.914-μm Q-switched Tm:YLF laser, high-peak-power stable laser pulse from gain-switched ~1.94-μm Tm
³⁺
-doped silica fiber lasers are reported for the first time. The slope efficiency was over 80% with respect to absorbed pump power, and chaotic spiking was effectively eliminated by using fast gain switching. With a 4-m Tm
³⁺
fiber, pulse energy of 1.3 mJ and pulsewidth of 61 ns were obtained, corresponding to peak power of 21.3 kW.