Simulation of Tm3+-doped silica and Er3+-doped fluorozirconate fibre lasers

Computer simulation of the operation of diode-pumped Tm3+-doped silica and Er3+-doped fluorozirconate fibre lasers that use cladding-pumping models high-power continuous-wave output at wavelengths near 2 and 3 mm. The model has been used to examine the fibre laser performance for a variety of fibre and pump configurations. Good agreement has been found between the model calculations and published experimental measurements. The model has determined the slope efficiency and relative performance of the fibre lasers when the pump wavelength was varied over the F-3(4) and H-3(4) absorption bands of Tm3+ and the I-4(11/2) absorption band of Er3+. The calculated maximum slope efficiencies were determined to be about 40, about 71 and about 31% respectively, for each absorption band pump scheme. The model was further used to analyse the fibre laser output when the Tm3+ and Er3+ dopant concentrations, absorption conditions and diffraction conditions are varied and the consequences on the operation of the fibre laser with these variations are discussed.