Intense emission at ∼3.3  µm from Er3+-doped fluoroindate glass fiber

Fluoroindate glass fibers with an E r 3 + doping concentration of ∼ 0.5 m o l % were fabricated by using a rod-in-tube method. Pumped by a 976 nm laser diode, intense emission at ∼ 3.3 µ m was obtained from a 40 cm long E r 3 + -doped fiber, which could be attributed to the transition 4 S 3 / 2 → 4 F 9 / 2 of E r 3 + ions. The calculated emission cross section at ∼ 3.3 µ m was ∼ 3 × 10 − 26 m 2 , which was ∼ 1.5 times larger than that of transitions E r 3 + : 4 F 9 / 2 → 4 I 9 / 2 and D y 3 + : 6 H 13 / 2 → 6 H 15 / 2 . In addition, broad emissions ranging from 3.1 µm to 3.85 µm were obtained in the E r 3 + -doped fiber under a 976 nm/1973 nm dual-wavelength pumping scheme. Our results indicated that E r 3 + -doped fluoroindate glass fibers had the potential for constructing efficient