Broadband and High Efficient 1530nm Emission from Oxyfluoride Glass Ceramics Codoped with Er ³⁺ and Yb ³⁺ Ions

The emission at 1530nm and its applications in optical communications
are discussed. The efficient width of the emission band Δ_eff, which is up to 91nm, is larger as compared with silica-based glass, bismuth glass and ZrF₄--BaF₂--LaF₃--AlF₃--NaF (ZBLAN) glass doped by Er ³⁺ ions. Under the excitation of 785\,nm laser, the emission integral intensity of 1530nm increases about five times in the glass ceramics higher than that in the glass. This is explained by the quantum cutting process by two-photon emission with phonon assistance. The results indicate that the glass ceramics are a promising candidate for developing broadband optical amplifiers in wavelength-division multiplexed systems.