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

Effective near-infrared emission covering the fifth optical telecommunication window (1380-1525 nm) has been observed in Pr ³⁺-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 (Δλ_eff) of the corresponding ¹D₂ → ¹G₄ transition emission is obtained to be 148 nm, and the maximum stimulated emission cross-section (σ_em) at 1467.5 nm is derived to be 1.29 × 10^-20 cm². The quantum efficiency of Pr ³⁺: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.