Comparative study of reflectivity and pump scheme effects on the efficiency of Tm3+-doped fibre laser at 1.72 μm

In this study, we revealed the impact of pumping scheme, fibre length, pumping power, and the reflectivity of the output fibre Bragg grating on the performance of a Tm3+-doped fibre laser (TDFL) operating at a wavelength of 1.72 μm. Numerical simulations enabled the optimization of output power and the reduction of losses due to reabsorption, as well as amplified spontaneous emission (ASE) around 1820 nm. The Tm3+-doped fibre (TDF) was bi-directionally pumped at 1570 nm to enhance pump absorption. The simulations suggest that a maximum power of 5.96 W at 1.72 μm and a slope efficiency of 64% are achievable using a Tm3+-doped silica fibre with a bi-directional pump of 4 W forward and 6 W backward.