Modeling of 1.7-μm and 2.4-μm Dual-Wavelength Pumped 4.3-μm Dysprosium-Doped Chalcogenide Fiber Lasers

A novel $1.7 \mu \text{m}$ and $2.4 \mu \text{m}$ dual-wavelength pumping scheme for a $4.3 \mu \text{m}$ dysprosium (Dy3+)-doped chalcogenide fiber laser was theoretically demonstrated. It was attributed to the $2.4 \mu \text{m}$ excited stated absorption (ESA, $^{6}\text{H}_{\mathrm {13/2}} \to ^{6}\text{H}_{\mathrm {9/2}},^{6}\text{F}_{\mathrm {11/2}}$ transition). Theoretically, when the two pumps were 5 W and 2 W, respectively, a laser power of 1.5 W with an remarkable efficiency of 30.2% was obtained from the home-made Dy3+:Ga0.8As34.2Sb5S60 glass fiber with a loss coefficient of 3 dB/m and a Dy3+ concentration of $3.67\times 10^{25}$ ions/m3. Results indicated that the dual-wavelength pumping scheme based on the gain fiber provides a potential way to $4.3 \mu \text{m}$ dysprosium-doped chalcogenide fiber lasers.