Material constraint‐based laser performance estimation of Yb³⁺‐doped phosphate fibers

Abstract

Based on the material properties of 47 Yb 3+ -doped phosphate fibers with different sizes and lengths, a laser performance estimation model was established to estimate the laser wavelength just above the threshold (λ th ), the laser threshold (P th ), and the laser slope efficiency (η). This model was solved via a numerical computing method with an accuracy of 0.01. Under the material constraints of this model, λ th , P th , and η were investigated by sensitivity analysis and Monte Carlo numerical simulation. The results show that short fibers with a small core diameter may more easily produce a shorter λ th . Additionally, for constant material properties, fibers with a longer λ th may have a lower P th and higher η than other fibers. Verifying the above conjecture, an output power of 8.7 W with 35% enhancement in slope efficiency was obtained from an optimized phosphate fiber for an optical path in which the output of the short-wave laser was inhibited. This model can be extended to simulate the lasing wavelength of multi-composition fibers, providing a theoretical basis for special laser bands, laser material preparation, and fiber structure design.