Pr3+-doped phosphate glasses for fiber amplifiers operating at 1.38–1.53 μm of the fifth optical telecommunication window

• ∼1.47 μm near-infrared emission is observed in Pr3+-doped phosphate glasses.
• Effective bandwidth of 1D2 → 1G4 transition emission is obtained to be 148 nm.
• ∼85% quantum efficiency of Pr3+:1D2 level is identified.
• Pr3+-doped practical oxide glass fiber amplifiers are expected to achieve.

Effective near-infrared emission covering the fifth optical telecommunication window (1380–1525 nm) has been observed in Pr3+-doped phosphate (LCBALP) glasses. Judd–Ofelt parameters Ω2 (9.17 × 10–20 cm2), Ω4 (16.50 × 10–20 cm2) and Ω6 (2.41 × 10–20 cm2) indicate a high inversion asymmetrical and strong covalent environment in the optical glasses. The effective bandwidth (Δλeff) of the corresponding 1D2 → 1G4 transition emission is obtained to be 148 nm, and the maximum stimulated emission cross-section (σem) at 1467.5 nm is derived to be 1.29 × 10–20 cm2. The quantum efficiency of Pr3+:1D2 level is identified to be 85.36%. The broad effective bandwidth and the large emission cross-section profile indicate that Pr3+-doped LCBALP glass fiber is promising in the realization of effective broadband amplification, especially at E- and S-band. As an expectation, the mature oxide glasses with Pr3+-doping, such as borate, phosphate and silicate glasses, are expected to be attractive candidates for broadband signal amplifiers operating at the fifth optical telecommunication window.