High-power diode-cladding-pumped Tm3+, Ho3+-doped silica fibre laser

The fundamental characteristics of a continuous-wave high-power diode-pumped Tm³⁺, Ho³⁺-doped double-clad silica fibre laser are presented. A maximum output power of 5.2 W was measured and was generated at a slope efficiency of 42 (44)% with respect to the launched (absorbed) pump power. At the optimum length of 7 m (α_effL = 2.9, where α_eff is the effective absorption coefficient of the fibre and L is the fibre length), the fibre laser output was measured to have a centre wavelength of 2105 nm and a line width of ∼ 20 nm. The centre wavelength of the emission was tunable over a 32-nm extent when 0.68 < α_effL < 3.28 or for a 6.2-m change in L.