Numerical Rate Equation Modeling of a ${\sim {\hbox {2.1}}-}\mu{\hbox {m}}-{\rm Tm}^{3+}/{\rm Ho}^{3+}$ Co-Doped Tellurite Fiber Laser

Judd-Ofelt analysis is performed on measurements of bulk samples of Tm³⁺- and Ho³⁺-doped tellurite glass from which the host-dependent Judd-Ofelt intensity parameters are extracted. These have then been used to calculate the radiative rates and branching ratios in this particular material system. A rate-equation approach is then used to model an experimentally realized ~2.1 μm Tm³⁺/Ho³⁺ codoped tellurite fiber laser and extract values of the energy transfer and upconversion rate parameters in TeO₂-ZnO-Na₂O (TZN) glass. Excellent agreement is found between simulated and experimental data, which indicates the validity of the approach.