Hybrid-pumped, gain-switched 1120  nm ytterbium-doped fiber laser

A monolithic, hybrid-pumped, gain-switched, single-mode, 1120 nm Yb-doped fiber laser is reported. Pumped by a 1064 nm pulse fiber source and a continuous-wave 976 nm laser diode, a record output pulse energy of 91.7 μJ at repetition rate of 10 kHz is obtained. The full width at half-maximum of the pulses is 4.1 μs, and the slope efficiency corresponding to the 1064 nm laser is more than 46%. The pulse build-up time and a pulsewidth decrease with an increase in the pump pulse energy are observed. In the gain-switched pulses, mode-lock-resembling pulses are detected. The subpulse's duration is about 415 ns, including the cavity round-trip time, and the width varied from 80 to 320 ns, which is longer than the traditional mode-locked laser.