Er ³⁺ –Yb ³⁺ codoped oxyfluoride germanate glass ceramics containing SrF ₂ nanocrystals for 1.5 µm optical amplification

Abstract Er 3+ –Yb 3+ codoped transparent oxyfluoride germanate glass ceramics (GCs) containing SrF 2 nanocrystals (NCs) have been prepared by melt quenching method. We have measured absorption, photoluminescence (PL), and PL decay. The PL spectra excited at 378 nm and 980 nm for 1.53 µm near‐infrared (NIR) and visible emission have been investigated. By using Judd–Ofelt (JO) theory, optical transition parameters have been calculated. Thanks to low phonon energy SrF 2 NCs and high fluorine oxyfluoride glass matrix, strong 1.53 µm emission with large measured lifetime ( τ meas ) are observed. After SrF 2 NCs formed, the intensity parameter Ω 2 becomes smaller for GC samples, the PL intensity and full width at half maximum increase. Absorption cross section ( σ a ) and emission cross section ( σ e ) at 1.5 µm have been calculated by McCumber theory. The luminescence efficiency ( η ), effective linewidth (Δ λ eff ), gain bandwidth ( σ e Δ λ eff ), and figure of merit ( σ e τ m ) have been evaluated. The results show excellent optical amplification performance.