The resonant pumping of holmium fibre lasers provides a fibre laser platform capable of addressing a wide range of
applications that benefit from operation at wavelengths beyond 2.1 μm. This architecture can provide laser devices that
promise high efficiency sources in the 2.1 μm spectral region with excellent beam quality and power scalability. This
paper presents our recent results of resonantly pumped pulsed and CW holmium fibre lasers. We have demonstrated the
first efficient resonantly cladding-pumped holmium fibre laser source. We have investigated both single mode and large
mode area fibres and achieved CW output powers of ~140 W with excellent beam quality. In addition to these CW lasers
we have investigated core-pumped, pulsed holmium fibre lasers and demonstrated output energies of up to 16 μJ at a
repetition rate of up to 600 kHz. These developments provide an opportunity to build a high average power, pulsed 2.1
μm laser for the purpose of power scaling future mid-infrared sources.
We present a power scalable, all-fibre, monolithic pulsed source based on a thulium doped fibre master-oscillator power
amplifier design. This source produced 200 μJ pulses with 20 - 40 ns duration at a repetition rate of up to 75 kHz
resulting in up to 12 W of linearly polarized light at 2.044 μm. This was used to pump a walk-off compensated ZnGeP2
optical parametric oscillator which generated 3 W in the mid-infrared, with a conversion efficiency of 25%.
We report on the development of a compact, all fibre laser source operating at 1 μm with a linearly polarized (extinction ratio > 20 dB) and very narrow linewidth (12 pm) output. The unique cavity design included a fibre Bragg grating high reflector and output coupler, inscribed via the point-by-point method directly into the active core. A single splice within the cavity between the fibre incorporating the high reflector and the output coupler permitted re-orientation of the stressors at an angle of 90 degrees to each other, which produced a single lasing polarisation. This simple technique removed the need for a more complicated and expensive polarization controller.