The comparative study of high efficiency of Tm³⁺-doped fiber laser at 1.72 μ m for different pump schemes

In this study, we revealed the impact of the pumping scheme, fiber length, pumping power, and reflectivity of the output fiber Bragg grating on the performance of a Tm^3+ -doped fiber laser (TDFL) operating at a wavelength of 1.72 μ m. Using numerical simulations, we optimized the output power and reduced losses due to reabsorption; as well as amplified spontaneous emission (ASE) at approximately 1820 nm. The Tm^3+ -doped fiber was bi-directionally pumped at 1570 nm to enhance the pump absorption. The simulations suggest that a maximum power of 5.96W at 1.72 μ m and a slope efficiency of 64 % are achievable using a Tm³⁺-doped silica fiber with a bi-directional pump of 4 W forward and 6 W backward.