Ho3+/Tm3+ codoped lead silicate glass for 2 μm laser materials

The mid-infrared emission of low phonon (963 cm−1) lead silicate glass system with Ho3+/Tm3+ co-doped has been investigated. Luminescence at ∼2.1 μm corresponding to 5I7 → 5I8 transition in holmium was obtained by energy transfer between Tm3+ and Ho3+ ions. Energy transfer mechanism between them was analyzed. And the highest value of the luminescence intensity was obtained in glass co-doped with 1Tm2O3/0.3Ho2O3. The full width at half maximum of the (Ho3+/Tm3+) emission reached to 350 nm in 1Tm2O3/0.1Ho2O3 sample. Absorption and emission cross section have also been calculated and analyzed. The maximum emission cross section was 3.9 × 10−21 cm2 around 2.0 μm. And when P > 0.4, a positive gain can be obtained at wavelengths >1941 nm. Results demonstrated that the prepared Ho3+/Tm3+ co-doped lead silicate glasses have excellent spectroscopic properties in mid-infrared wavelengths and can obtain high gain in fiber lasers.