A linearly polarised, pulsed Ho-doped fiber laser

We report the highest power operation of a monolithic polarised gain-switched holmium fiber laser. In this paper we describe the pulsed operation of two monolithic holmium fiber lasers, which were gain-switched by a pulsed thulium fiber laser. The first holmium laser produced pulses with a minimum pulse duration of 85 ns, maximum pulse energy of 16 μJ and repetition rate of 600 kHz. This laser was linearly polarised with an extinction ratio of >18.5 dB under all operating conditions and achieved average powers of up to 5.1 W at 2.104 μm. The second laser demonstrated shorter pulses with a minimum duration of 38 ns at a maximum repetition rate of 300 kHz. This laser produced up to 1.5 W of average power at 2.112 μm.